from CSS1Contents
This appendix is informative, not normative.
CSS 2.1 is an updated revision of CSS2. The changes between the CSS2 specification (see [CSS2]) and this specification fall into five groups: known errors, typographical errors, clarifications, changes and additions. Typographical errors are not listed here.
This chapter is not a complete list of changes. Minor editorial changes and most changes to examples are also not listed here.
New color value: 'orange'
New 'display' value: 'inline-block'
New 'content' values 'none' and 'normal'. (The values 'none' and 'normal' are equivalent in CSS 2.1, but may have different functions in CSS3.)
New 'white-space' values: 'pre-wrap' and 'pre-line'
New 'cursor' value: 'progress'
This new section is added to explain the motivation for CSS2.1 and its relation to CSS2.
This section (formerly Section 1.1) has been marked non-normative.
This section (formerly Section 1.2) has been marked non-normative.
This section (formerly unnumbered under 1.3.2) notes that value types are specified in terms of tokens and that spaces may appear between tokens in values. A note explains that spaces are required between some tokens.
This section (formerly unnumbered under 1.3.2) now declares the Media line in property definitions to be non-normative.
A new line is added to each property definition specifying what the computed values are for the property. (This defines what level of computation is done to a property value before inheritance and before certain other calculations.)
This section (formerly 1.3.4) now specifies that HTML examples lacking DOCTYPE declarations are SGML Text Entities conforming to the HTML 4.01 Strict DTD [HTML4]. The markup for many examples has been reformulated to either include a DOCTYPE or conform to this definition.
This section (formerly 1.4) has been updated to reflect contributions to CSS2.1 and has been marked non-normative.
Support for user style sheets is now required (in most cases), rather than just recommended.
Support for turning of author style sheets is now required.
Application of CSS properties to form controls is explicitly undefined. Authors are recommended to treat form control styling capabilities in UAs as experimental.
This section changed to say that error handling is specified in most cases.
Added INVALID token and rules for its definition.
An optional hyphen, "-", is now allowed at the beginning of an "ident" for vendor extensions. (See section 4.1.2.1)
The underscore character ("_") is allowed in identifiers. The definitions of the lexical macros "nmstart" and "nmchar" now include it. See also section 4.1.2.1 (Vendor extensions).
The "escape" macro has been modified to allow the escaping of any character except newlines, form feeds, and hex digits (to avoid conflict with unicode escapes).
Modified "string1" and "string2" macros by defining allowed characters through excluding disallowed characters. This allows invisible ASCII characters to be included in a string.
Updated prose about identifiers (second bullet point) to match changes in the tokenization (above).
Excluded null (0x0) character from CSS numerical escapes and indicate that it is undefined in CSS2.1 what happens if such a character is encountered.
Allowed the use of U+FFFD as a replacement for characters outside the range allowed by Unicode.
CSS is no longer case-insensitive, but case-sensitive with exceptions. Changed "All CSS style sheets are case-insensitive, except for parts that are not under the control of CSS" to "All CSS syntax is case-insensitive within the ASCII range (i.e. [a-z] and [A-Z] are equivalent), except for parts that are not under the control of CSS." See also the change to case-sensitivity of counters in 4.3.5.
Defined parsing in the cases of Malformed Declarations, Unexpected End of Stylesheet, and Unexpected End of String.
Sections 4.3.7 (Angles), 4.3.8 (Times), and 4.3.9 (Frequencies) have been moved to the informative Appendix A.
Added a paragraph on heuristics for finding the x-height of a font.
Updated URI references to RFC3986.
Changed "Counters are denoted by identifiers" to "ounters are denoted by case-sensitive identifiers" (see also the change to case-sensitivity in 4.1.3).
Defined the numeric values corresponding to color keywords instead of referencing HTML4 for those values.
UAs are now allowed to intelligently map colors outside the gamut into the gamut instead of simply clipping them into the range of the gamut.
Added this section to recommend that unsupported properties and values be ignored as if they were invalid.
Changed character encoding detection rule 2 to include a BOM and referred to additional rules below.
Added rule 4 to provide for use of the referring style sheet or document's character encoding.
Added rule 5 to require falling back to UTF-8.
Removed the restriction on using @charset in embedded style sheets.
Allowed a BOM to precede the @charset rule.
Added requirement that @charset rule must be a literal '@charset"...";', not a CSS-syntax equivalent.
Added requirement to support for UTF-8 at minimum.
Specified that any @charset rule not at the beginning of the style sheet must be ignored.
Removed note on theoretical problem with @charset problem and precisely defined rules for character encoding detection based on @charset and/or BOM.
Specified that UAs must ignore style sheets in unknown encodings.
RFC 3066 replaces RFC 1766.
Class selectors are allowed for other formats than HTML.
Added a note about matching classes in formats with multiple class attributes per element. The behavior is non-normative, because, at the time of writing, there exist no such formats.
Specified how to match elements with two or more ID attributes.
Removed exception for HTML UAs that allowed them (and only them) to ignore ':first-letter' and ':first-line'.
UAs may return a :visited link to :link status at some point. (This was previously a note, but is now normative.)
Added a note about privacy concerns with link pseudo classes and allowed UAs to treat :visited as :link.
The identifier C in ':lang(C)' need not be a valid language code, but it must not be empty.
':first-line' also applies to inline blocks, table captions and table cells. Added a definition of "first formatted line" to make the rules about which line is the first line more precise.
UAs are no longer forbidden from applying more properties than the given list.
More precise definition of first letter. Added rules for cases where the first letter is in an inline block or table cell. Added rules for cases when preceding punctuation is in a different element from the first letter itself.
UAs may apply other properties to first letters than the given list.
Unicode character classes Pi and Pf added to the definition of punctuation.
Redefined "computed value" and created the concept of "used value" so that inheritance can be performed without laying out the document. This change has the effect of allowing (requiring) percentages to be inherited as percentages and affects many other layout calculations throughout the spec.
Since computed value of a property can now also be a percentage. In particular, the following properties now inherit the percentage if the specified value is a percentage:
Note that only 'text-indent' inherits by default, the others only inherit if the 'inherit' keyword is specified.
Changed suggestion that user be able to turn off author styles to a requirement.
The "style" attribute now has a higher specificity than any style rule.
Pseudo-elements are now counted with elements in calculating a a selector's specificity.
"Non-CSS presentational hints" no longer exist, with the exception of a small set of attributes in HTML.
Added 'speech' media type.
Marked "Media" field in property descriptions informative.
Marked this section informative.
Added sound to 'handheld' in media type/media group table.
Changed 'tactile' to be both 'static' and 'interactive'.
If the containing block's width depends on an element with percentage margins, then the resulting layout is undefined in CSS 2.1.
In the definition of "collapsing margins", added "non-empty content" and "clearance" to the parenthetical list of things that prevent consecutive margins from being adjoining.
Vertical margins of elements with 'overflow' other than 'visible' no longer collapse with their in-flow children.
Defined how margins collapse through an element with adjoining top and bottom margins.
Added that margins of the root element's box do not collapse.
More rigorously defined "adjoining" for margin collapsing.
Sixth bullet, second sub-bullet: to find the position of the top border edge, assume the element has a bottom (rather than top) border.
If the containing block's width depends on an element with percentage padding, then the resulting layout is undefined in CSS 2.1.
'transparent' can now be specified independently for each border side, on par with <color>.
3D border styles ('groove', 'ridge', 'inset', 'outset') now depend on the corresponding border-color rather than on 'color'.
Added this new section to specify layout of inline boxes when affected by bidi.
Removed paragraphs about the initial containing block, as this is now defined differently. (See changes to section 10.1.)
Added a paragraph to define formatting when an inline box contains a block box.
Specified what property values are applied to anonymous boxes.
Specified that collapsed white space does not generate anonymous inline boxes.
Changed run-in rules so that a) run-ins that contain blocks become blocks b) run-ins can only run into sibling blocks and c) run-ins cannot run into other run-ins.
The 'marker' and 'compact' values of the 'display' property are not part of CSS 2.1. Text relating to these values has been removed throughout the specification.
Defined the computed value of 'display' as the specified value except for positioned and floating elements and for the root element. The computed value of 'display' for these elements is defined in section 9.7 and is slightly different from the definition in CSS2.
Conforming HTML UAs are no longer allowed to ignore the 'display' property.
The 'position' property now applies to all elements, including generated content.
The effect of relative positioning on table captions and internal table elements is undefined in CSS 2.1.
For fixed positioning, introduced a conflict between this section and section 10.1 rule 3. See howcome for rationale.
Forbid UAs from paginating the content of fixed boxes.
UAs are allowed to treat all values of 'position' as 'static' on the root element.
Defined computed values of 'top', 'right', 'bottom', 'left' based on the value of 'position'.
Percentage offsets are no longer undefined for containing blocks without an explicit height.
Specified that floats, absolutely positioned elements, inline-blocks, table-cells, table-captions, and elements with 'overflow' other than 'visible' establish new block formatting contexts.
In the paragraph about the position of a box's outer edge with respect to its containing block, except boxes that establish a new block formatting context, as they may become narrower due to floats.
Specified that the effect of 'justify' on the content of a line box does not affect the contents of inline-table and inline-block boxes.
Empty line boxes are now required to be treated as zero-height and ignored in margin collapsing.
Added several paragraphs and an example to explain exactly what the computed values of relatively-positioned offsets are, how they affect each other, and what happens when the positioning is overconstrained. (These were not previously defined.)
Floats are no longer required to have an explicit width.
Floats outside of line boxes no longer align to the bottom of the preceding block box; it is implied that they are initially aligned with their non-floated position.
Specified that "If a shortened line box is too small to contain any further content, then it is shifted downward until either it fits or there are no more floats present."
Specified that the border box of a table, block-level replaced element, or element in the normal flow that establishes a new block formatting context must not overlap any floats in the same block formatting context.
The 'float' property now also applies to :before/:after and generated content.
UAs are now allowed to treat all values of float as 'none' on the root element.
Added to rule 4 prose to define the position of a float when it occurs between two collapsing margins.
Defined clearance to precisely detail the 'clear' property's effect on margin collapsing and the block's cleared position.
Added note to explain effect of 'clear' on inline elements since CSS1 (but not CSS2 or CSS 2.1) allows 'clear' on inline elements.
Changed rules to convert 'display' not always to 'block', but to an appropriate block-level display value as given by a mapping table.
Added rule 4 to convert root element's 'display' value according to the mapping.
Specified that the background and borders of an element that forms a stacking context are behind all of its descendants, altered stacking context prose to be more precise, and added a normative Appendix E: Elaborate description of Stacking Contexts to be even more precise about the position of borders, backgrounds, and content on the z-axis.
Conforming UAs are now allowed to not support bidirectional text; in this case they must ignore the 'direction' and 'unicode-bidi' properties. However since applying bidi can have an effect even when a document doesn't contain right-to-left characters, UAs that do support bidi are no longer permitted to not apply the algorithm just because the document lacks right-to-left characters.
Added a paragraph to define precisely how the Unicode bidirectional algorithm applies to text in the CSS formatting model and how the CSS 'direction' property on blocks maps into the algorithm.
Conforming HTML UAs are no longer exempt from supporting 'direction' and 'unicode-bidi'.
Updated prose to use the terms "specified", "computed" and "used" as appropriate when referencing values. This affects many calculations in this section. (See changes to section 6.1.)
In rule 1, defined the initial containing block as the viewport for continuous media and the page area for paged media. (It was previously undefined.)
In rule 2, defined the page area as the containing block for fixed positioned elements in paged media.
In rule 4.1, when the containing block of an absolutely-positioned element is formed by an inline-level element, it is now formed by that element's padding edges, not its content edges.
In rule 4, changed the containing block for absolutely positioned elements with only statically positioned elements from the root's content box to the initial containing block.
Specified the positioning and breaking behavior of absolutely-positioned elements in paged media.
Declared that if the containing block's width depends on an element's percentage width, then the resulting layout is undefined in CSS 2.1.
The computed values of 'left' and 'right' for are now defined in section 9.3.2. The value 'auto' does not always compute to zero.
Added sections 10.3.9 and 10.3.10 to define calculations for inline blocks.
The sizing algorithm for replaced elements now takes into account and attempts to preserve the replaced content's intrinsic ratio. Sizing of replaced elements with percentage intrinsic sizes and without intrinsic sizes is now also defined.
The effect of percentage intrinsic widths is now undefined for CSS level 2, rather than ignored.
Specified that a computed total of the width, padding, and borders that is greater than the containing block width causes auto margins to be treated as zero in the rest of the rules. This avoids 'auto' margins being negative on the start edge.
Applied changes to section 10.3.2 and section 10.3.3 to block-level replaced elements in normal flow by referring to the calculations in those sections.
Defined computations for 'auto' width floats as shrink-to-fit. (Floats were previously required to have fixed widths.)
Applied changes to section 10.3.2 to this section by referencing it for 'auto' width calculations.
Defined the static position of an element more precisely.
Rewrote constraint rules.
The 'direction' property of the containing block of the static position determines which side is clamped to the static position, not the 'direction' property of the containing block of the absolutely positioned element.
In rule 1, applied sizing rules from section 10.3.2.
In rule 2 (formerly rules 2 and 3), referred to new definition of 'static position' in section 10.3.7.
Also in rule 2, the 'direction' property of the containing block of the static position determines which side is clamped to the static position, not the 'direction' property of the containing block of the absolutely positioned element.
In rule 4 (formerly rule 5), prevented 'auto' left and right margins in resulting in a negative margin on the start edge.
Specified that if the containing block's width is negative, the used value of a percentage min/max width is zero.
Specified that if the min/max width is specified in percentages and the containing block's width depends on this element's width, then the resulting layout is undefined in CSS 2.1.
The UA is no longer allowed to select an aribtrary minimum width.
The used width of replaced elements with an intrinsic ratio and both 'width' and 'height' specified as 'auto' is now calculated according to a table designed to preserve the intrinsic ratio as much as possible within the given constraints.
Removed mention of 'line-height' for inline elements since their content box height no longer depends on 'line-height'.
Percentage heights on absolutely-positioned elements are no longer treated as 'auto' when the containing block's height is not explicitly specified. Added a note to explain why this is possible.
Specified that a percentage height on the root element is relative to the initial containing block.
The computed values of 'top' and 'bottom' for are now defined in section 9.3.2. The value 'auto' does not always compute to zero.
Added section 10.6.6 to cover cases that are no longer covered under the previous sections.
Added section 10.6.7 to define 'auto' heights for block formatting context roots. (Unlike other block boxes, the height of these boxes increases to accomodate any normal-flow descendant floats.)
The height of an inline box is no longer given by the 'line-height' property and is now undefined. This section now suggests that the height of the box can be based on the font.
The sizing algorithm for replaced elements now takes into account and attempts to preserve the replaced content's intrinsic ratio. Sizing of replaced elements with percentage intrinsic sizes and without intrinsic sizes is now also defined.
Specified that for inline elements, the margin box is used when calculating the height of the line box.
This section now only applies to elements whose 'overflow' value computes to 'visible'; elements with other values of 'overflow' are discussed in the new section 10.6.7 ('Auto' heights for block formatting context roots).
Defined the static position of an element more precisely.
Rewrote constraint rules.
In rule 1, applied sizing rules from section 10.6.2.
Percentage min/max heights on absolutely-positioned elements are no longer treated as '0'/'none' when the containing block's height is not explicitly specified. However if the containing block's width depends on an element's percentage width, then the resulting layout is undefined in CSS 2.1.
The used width of replaced elements with an intrinsic ratio and both 'width' and 'height' specified as 'auto' is now calculated according to a table designed to preserve the intrinsic ratio as much as possible within the given constraints.
Added rule 4 to specify that the height of the line box must be at least as much as that specified by the 'line-height' property on the this block.
UAs are no longer permitted to clip content to the line box, and are instead asked to render overlapping boxes in document order.
'line-height' set on a block no longer specifies the minimal height of each inline box; instead it specifies the minimal height of each line box. The exact effect of this requirement is expressed in terms of struts; it is affected by vertical-alignment.
Adjusted text to reflect that the content box height of an inline is no longer dictated by the 'line-height' property.
Since the content box is now defined by the font and not by the line-height, 'text-top' and 'text-bottom' refer to the content area instead of the font.
Defined 'top' and 'bottom' alignment in terms of aligned subtrees to take into account any protruding descendants.
Defined the baseline of inline tables and inline blocks.
Specified that 'overflow' clips to the padding edge.
'projection' media are no longer permitted to print overflowing content for 'overflow: scroll'. 'print' media now may, as opposed to should.
UAs are now required to apply the 'overflow' property set on the root element to the viewport. Additionally, HTML UAs must use the 'overflow' property on the HTML BODY element instead if the root element's 'overflow' value is 'visible'.
Specified placement of scrollbar in the box model.
The width of any scrollbars is no longer included in the width of the containing block. (And consequently, all text in section 10.3 that subtracts the scrollbar width from the containing block width has been removed.)
The 'clip' property now applies only to absolutely positioned elements. Furthermore, it applies to those elements even when their 'overflow' is 'visible'.
The default value of 'clip', 'auto', now indiciates no clipping rather than clipping to the element's border box.
Values of "rect()" should be separated by commas. UAs are required to support this syntax, but may also support a space-separated syntax since CSS2 was not clear about this.
While CSS2 specified that values of "rect()" give offsets from the respective sides of the box, current implementations interpret values with respect to the top and left edges for all four values (top, right, bottom, and left). This is now the specified interpretation.
The 'visibility' property is now defined to inherit, and descendant elements can override an ancestor's hidden visibility.
Moved all discussion of aural rendering to Appendix A.
Removed restrictions on which properties and property values are allowed on ':before' and ':after' pseudo-elements.
The initial value of 'content' is now 'normal', not the empty string.
The 'content' property now distinguishes between the empty string, which creates an empty box; and 'normal'/'none', which create no box at all. (There is no distinction between 'normal' and 'none' in level 2.)
A UA is now allowed to report a URI that fails to download.
Removed recommendation to authors to put rules with media-sensitive 'content' properties inside '@media'.
Whether '\A' escapes in generated content create line breaks is now subject to the 'white-space' property.
The former section 12.3 on interaction between ':before', ':after' and elements with 'display: compact' or 'display: run-in' has been removed. (The interaction is already fully defined, because generated content consists of boxes in the tree, no different from other boxes.)
Specified that extra 'close-quote's and 'no-close-quote's (those without a matching 'open-quote' or 'no-open-quote') are not rendered, and that neither 'close-quote' nor 'no-close-quote' cause the quoting depth to be negative.
Defined what a rule with duplicate counters, such as 'counter-reset: section 2 section', means.
The scope of a counter no longer defaults to the whole document, but starts at the first element that uses the counter. (This affects counters that are used without a prior 'counter-reset' to set the scope explicitly.)
Removed text in section 12.5 (formerly 12.6) relating to the 'marker' display value.
Removed the 'marker-offset' property (and thus former section 12.6.1).
The list styles 'hebrew', 'armenian', 'georgian', 'cjk-ideographs', 'hiragana', 'katakana', 'hiragana-iroha' and 'katakana-iroha' have been removed due to lack of implementation experience. (They are expected to return in the CSS3 Lists module.)
Removed the sentence that said that an unknown value for 'list-style-type' should cause the value 'decimal' to be used instead. Instead, normal parsing rules apply and cause the rule to be ignored.
The size of list style markers without an intrinsic size is now defined.
The 'size', 'marks', and 'page' properties are not part of CSS 2.1.
The requirement for UA's to honor different declarations for :left, :right, and :first pages has been softened to simplify implementations: the page area of the :first page may be used for :left and :right pages as well.
UAs are now only required to apply the page break properties to block-level elements in the normal flow of the root element, not to other blocks.However, UAs are now permitted to apply these properties to elements other than block-level elements.
Defined treatment of margins, borders, and padding when a page break splits a box.
The 'page-break-inside' property no longer inherits.
The 'page-break-inside' property of all ancestors is checked for page-breaking restrictions, not just that of the breakpoint's parent.
When dropping restrictions to find a page breaking opportunity, rule A is dropped together with B and D rather than together with C.
Removed restriction on breaking within absolutely positioned boxes.
For 'background-position', the restriction that keywords cannot be combined with percentage or length values is removed. I.e., a value like: '25% top' is now allowed. Also, 'background-position' now applies to all elements, not just to block-level and replaced elements.
User agents are no longer allowed to treat a value of 'fixed' for 'background-attachment' as 'scroll'. Instead they must ignore all such declarations as if 'fixed' were an invalid value.
The size of background images without an intrinsic size is now defined.
The contents of this section is now a non-normative note.
The 'font-stretch' and 'font-size-adjust' properties have been removed in CSS 2.1.
Font descriptors, the '@font-face' declaration, and all associated parts of the font matching algorithm have been removed in CSS 2.1.
In this section (previously 15.5), in step 5 (prevously 8) of the font matching algorith, the UA is now allowed to use multiple default fallback fonts to find a glyph for a given character.
In the per-property rule 2, specified that if there is only a small-caps font in a given family, then that font will be selected by 'normal'.
The "missing character" glyph is no longer considered a match for the last font in a font set, but is now considered a match for U+FFFD.
Certain punctuation characters when appearing in unquoted font family names are now required to be escaped.
The 'font-variant' property's effect is no longer restricted to bicameral scripts.
The computed value of 'font-weight' has been defined more precisely such that the 'bolder' and 'lighter' values have an appropriate effect when inheriting through elements with different font-families.
Removed suggestion of 1.2 fixed ratio between keyword font sizes in favor of notes recommending a variable ratio and a smallest font-size no less than 9 pixels per EM unit.
Added table mapping CSS font-size keywords to HTML font size numbers.
The 'text-shadow' property is not in CSS 2.1.
The initial value of 'text-align' is no longer UA-defined but a nameless value that acts as 'left' if 'direction' is 'ltr', 'right' if 'direction' is 'rtl'.
The <string> value for 'text-align' is not part of CSS 2.1.
For 'text-align', specified that 'justify' is treated as the initial value when computed value of 'white-space' is 'pre' or 'pre-line'.
More precisely defined what boxes are affected by text decorations specified on a given element.
Specified that underlines, overlines, and line-throughs apply only to text.
Specified that an underline, overline, or line-through applied across a line must be at a constant vertical position and with a constant thickness across the entire line.
Specified how text decorations are affected by relative positioning on descendants.
User agents are now allowed to recognize the 'blink' value but not blink, whereas before they were required to ignore the 'blink' value if they chose not to support blinking text.
Added text to allow older UAs to conform to this section if they follow CSS2's 'text-decoration' requirements but not the additional requirements in CSS2.1.
Support for the various values of 'letter-spacing' and 'word-spacing' is no longer optional.
Specified that word spacing affects each space, non-breaking space, and ideographic space left in the text after white space processing rules have been applied.
UAs are no longer allowed to not transform characters for which there is an appropriate transformation but which are outside of Latin-1.
The 'white-space' property now applies to all elements, not just to block-level elements.
"\A" in generated content no longer forces a break for 'normal' and 'nowrap' values of 'white-space'.
Specified that the CSS white space processing model assumes all newlines have been normalized to line feeds.
Added section 16.6.1 to precisely define white space handling.
Added section 16.6.3 to specify handling of control and combining characters.
Moved all discussion of aural rendering and related properties to Appendix A.
Updated prose to use the terms "specified", "computed" and "used" as appropriate when referencing values. (See changes to section 6.1.)
Defined handling of multiple 'table-header-group' and 'table-footer-group' elements.
UAs are no longer allowed to ignore the table display values on arbitrary HTML elements, only on HTML table elements.
Changed rules so that internal table elements without an enclosing 'table' or 'inline-table' box generate an anonymous 'inline-table' rather than an anonymous 'table' when inside a "display: inline" parent element.
The anonymous table object rules now treat anonymous boxes as equal to elements' boxes. Replaced several instances of the term "element" with "box", removed several instances of "(in the document tree)" and clarified that anonymous boxes generated in earlier rules are part of the input to later rules. Also replaced the term "object" with "box", as is used throughout the rest of the specification.
HTML UAs are no longer exempt from the anonymous box generation rules.
The relationship of the caption box, table box, and outer anonymous table box has been changed as follows:
The 'left' and 'right' values on 'caption-side' have been removed.
Changed rule 5 in grid layout rules to allow overlapping of table cells instead of leaving skipping a gap in the grid to avoid overlap.
In point 6, changed 'These "empty" cells are transparent' to:
If the value of their 'empty-cells' property is 'hide' these "empty" cells are transparent through the cell, row, row group, column, and column group backgrounds, letting the table background show through.
Specified that in fixed table layout, extra columns in rows after the first must not be rendered.
Restricted inputs to the table layout algorithm for 'table-layout: auto', whether or not the algorithm described in this section is used, to the width of the containing block and the content of, and any CSS properties set on, the table and any of its descendants.
Added rule 4 to include the column group's width in the algorithm for determining column widths.
The 'height' property on tables is now treated as a mininimum height; the UA no longer has the option of using 'height' to constrain the size of the table to be smaller than its contents.
Percentage heights on table cells, rows, and row groups now compute to 'auto'.
The baseline of a cell is now defined much more precisely.
Defined the baseline of a row with no baseline-aligned cells.
The <string> value for 'text-align' is not part of CSS 2.1.
Several popular browsers assume an initial value for 'border-collapse' of 'separate' rather than 'collapse' or exhibit behavior that is close to that value, even if they do not actually implement the CSS table model. 'Separate' is now the initial value.
Specified the effect of padding on the table element.
Specified which parts of the table are included in the width measurement.
Refined definition of "empty" when used as a condition for the 'empty-cells' property so that it is not triggered when the cell includes any child elements, even if they are empty.
The 'empty-cells' property now hides both borders and backgrounds, not just borders.
Changed behavior of a row when it collapses due to 'empty-cells': it is no longer treated as "display: none". Instead it is given zero height and its associated border-spacing is eliminated.
The outer half of the table borders no longer lie in the margin area. Specified which part of the table is considered the border are in the collapsed borders model and how its width is calculated. The edges of the box in which the table background is painted is, however left explicitly undefined.
Defined in rule 4 what happens when two elements of the same type conflict and their borders have the same width and style.
The size of cursors without an intrinsic size is now defined.
Position of outline with respect to the border edge is now only suggested, not required.
Conformant UAs are now allowed to ignore the 'invert' value. In such UAs the initial value of 'outline-color' is the value of the 'color' property.
The 'marker' value for 'display' does not exist in CSS 2.1
Chapter 19 on aural style sheets has become appendix A and is not normative in CSS 2.1. Related units (deg, grad, rad, ms, s, Hz, kHz) are also moved to this appendix, as is the 'speak-header' property from the "tables" chapter and other notes on aural table rendering. The 'aural' media type is deprecated in favor of the new 'speech' media type.
Changed the initial value of 'pause-before' and 'pause-after' to be 0 instead of UA-defined.
A note has been added to this section (formerly 19.4) about the change in position and behavior of pauses in CSS3 Speech compared to this appendix.
This section (formerly Section 19.5) now specifies the placement of cues and pauses with respect to the :before and :after pseudo-elements.
The keywords 'mix' and 'repeat' may now appear in either order.
Various references in Appendix B (formerly Appendix E) have been updated as appropriate.
Switched [CSS1] from Normative to Informative.
Updated URI reference from [RFC1808] and the draft-fielding-uri-syntax-01.txt to [RFC3986].
Updated HTTP reference from [RFC2068] to [RFC2616].
Removed normative references to [IANA] and [ICC32].
Added normative references to [ICC42], [RFC3986], [RFC2070], [UAAG10].
Added informative references to CSS2, CSS3 Color, CSS3 Lists, Selectors, CSS3 Speech, DOM 3 Core, MathML 2, P3P, RFC1630, SVG 1.1, XHTML 1, XML ID, and XML Namespaces.
Removed informative references to [ISO10179] (DSSSL), [INFINIFONT], [ISO9899] (C), [MONOTYPE], [NEGOT], [OPENTYPE], [PANOSE], [PANOSE2], [POSTSCRIPT], [RFC1866] (HTML 2), [RFC1942] (HTML Tables), [TRUETYPEGX], [W3CStyle].
Updated language tags references from [RFC1766] to [3066].
The former informative appendix C, "Implementation and performance notes for fonts," is left out of CSS 2.1.
Shorthand properties take a list of subproperty values or the value 'inherit'. One cannot mix 'inherit' with other subproperty values as it would not be possible to specify the subproperty to which 'inherit' applied. The definitions of a number of shorthand properties did not enforce this rule: 'border-top', 'border-right', 'border-bottom', 'border-left', 'border', 'background', 'font', 'list-style', 'cue', and 'outline'.
The "applies to" line of many property definitions has been made more accurate by excluding or including table display types where appropriate.
DELIM should not have included single or double quote. Refer also to section 4.1.6 on strings, which must have matching single or double quotes around them.
Removed "A-Z" from the "nmchar" token: as CSS is case insensitive anyway, it was redundant.
Corrected "unicode" macro to treat CRLF as a single character.
Corrected "block" production to allow white space between declarations.
In the rule for "any" (in the core syntax), corrected "FUNCTION" to "FUNCTION any* ')'".
Corrected third paragraph to say that an '@import' rule can only be preceeded by an '@charset' rule or other '@import' rules.
Several values described in subsections of this section incorrectly allowed two "+" or "-" signs at their beginnings.
Fixed double sign error in definition of <length>. (<number> already has a sign.)
Corrected the suggested reference pixel to be based on a 96 dpi device, not 90 dpi. The visual angle is thus about 0.0213 degrees instead of 0.0227, and a pixel at arm's length is about 0.26 mm instead of 0.28
Corrected last sentence to refer to a unsupported used length, not an unsupported specified length.
Fixed double sign error in definition of <percentage>. (<number> already has a sign.)
Defined escaping requirements in terms of the URI token so that no escaping requirements are missing from the prose.
Included invalid URIs in last paragraph about URI error handling.
Corrected syntax of counter() and counters() notation to allow white space between tokens.
Deleted the comments about range restriction after the following examples:
em { color: rgb(255,0,0) }
em { color: rgb(100%, 0%, 0%) }
(Formerly section 4.3.10) Corrected text to allow all forms of Unicode escapes for U+000A, not just the "\A" form, for including newlines in strings.
In the second bullet, added that the ':lang()' pseudo-class can also be deduced from the document in some cases.
Removed paragraph about imported style sheets being overridden by rules in the importing style sheet: imported style rules follow the cascade as specified in 6.4.1 Cascading order, exactly as if they were inserted in place of the @import rule.
The definition of "content edge" has been changed to depend on 'width' and 'height' rather than directly on 'rendered content'.
From the definition of "padding edge", deleted the sentence "The padding edge of a box defines the edges of the containing block established by the box." For information about containing blocks, consult Section 10.1.
The colors in the example HTML did not match the colors in the image.
Changedvarious border shorthands' syntax definitions to use the <border-width>, <border-style> and <'border-top-color'> value types as appropriate.
Excepted table elements from second paragraph about principal block boxes and their contents.
Corrected sentence to say "either only block boxes or only inline boxes" instead of "only block boxes".
In the definition of "position: static", added 'right' and 'bottom' to the sentence saying that 'top' and 'left' do not apply.
The properties 'top', 'right', 'bottom', and 'left', incorrectly referred to offsets with respect to a box's content edge. The proper edge is the margin edge. Thus, for 'top', the description now reads: "This property specifies how far a box's top margin edge is offset below the top edge of the box's containing block."
Corrected text under property definitions to say that for relatively-positioned elements, 'top', 'right', 'bottom', and 'left' define the offset from the box's position in the normal flow, not from the edges of the containing block. (The previous definition conflicted with that was further down; since that text is now redundant, it has been removed.)
In paragraph about relationship of a box's outer edges to its containing block's edges, corrected parenthetical to say that line boxes, not the content area, may shrink due to floats.
Added "and the presence of floats" to "The width of a line box is determined by a containing block".
In the first paragraph, added "or floated" to the phrase "laid out according to the normal flow" as floated elements can be relatively positioned but are not part of the normal flow.
Corrected sentence about not enough horizontal room for the float to say that it is shifted downward until either it fits or there are no more floats present.
Correct "Applies to" line and prose to say that the 'float' property can be set for any element but only applies to elements that are not absolutely positioned.
Removed sentence saying that 'clear' may only be specified for block-level elements: it can be specified for any element, it only applies to block-level elements.
Corrected sentence that said absolutely positioned boxes establish a new containing block for absolutely positioned descendants to except fixed positioned descendants.
In rule 1, corrected "user agents must ignore 'position' and 'float" to "'position' and 'float' do not apply".
Corrected note about 'direction' on table column elements to say that "columns are not the ancestors of the cells in the document tree" rather than saying "columns don't exist in the document tree".
Added table cells, table captions, and inline blocks alongside block-level elements in description of 'bidi-override' value. Also corrected the prose to handle anonymous child blocks.
Updated mention of Unicode's embedding limit from 15 to 61.
Included table cells (and inline blocks) together with block-level elements in rule 2 defining the containing block of non-absolutely-positioned elements.
In the last sentence of the paragraph following the equation ("If the value of 'direction' is 'ltr', this happens to 'margin-left' instead") substituted 'rtl' for 'ltr'.
The initial value for 'min-width' is now '0' rather than UA-dependent.
Corrected "applies to" exception for both 'min-width' and 'max-width' from "table elements" to "table rows and row groups".
Specified that negative values for 'min-width' and 'max-width' are illegal.
Added that 'auto' height also depends on whether the element has padding or borders, as these influence margin-collapsing behavior.
Added text to correctly account for margin collapsing behavior.
Corrected "applies to" exception for both 'min-width' and 'max-width' from "table elements" to "table columns and column groups".
Specified that negative values for 'min-height' and 'max-height' are illegal.
Corrected "applies to" line for 'overflow' from "block-level and replaced elements" to "non-replaced block-level elements, table cells, and inline-block elements".
The example of a DIV element containing a BLOCKQUOTE containing another DIV was not rendered correctly. The first style rule applied to both DIVs, so the second DIV box should have been rendered with a red border as well. The second DIV has now been changed to a CITE, which doesn't have a red border.
Corrected "rect (<top> <right> <bottom> <left>)" to "rect(<top>, <right>, <bottom>, <left>)".
Corrected initial value of 'visibility' to 'visible'.
The example used the style 'hebrew', which doesn't exist in CSS level 2. Changed to 'lower-greek'.
Under the 'list-style' property, the example:
ul > ul { list-style: circle outside } /* Any UL child of a UL */
could never match valid HTML markup (since a UL element cannot be a child of another UL element). An LI has been inserted in between.
Second sentence: "In terms of the box model, 'background' refers to the background of the content and the padding areas" now also mentions the border area. (See also errata to section 8.1 above.) Thus:
In terms of the box model, "background" refers to the background of the content, padding and border areas.
Under 'background-image', defined the image tile size used when the background image has intrinsic sizes specified in percentages or no intrinsic size.
Under 'background-repeat', the sentence "All tiling covers the content and padding areas [...]" has been corrected to
"All tiling covers the content, padding and border areas [...]".
Under 'background-attachment', the value 'scroll' is defined to scroll with the "containing block" rather than with the "document". Also the sentence "Even if the image is fixed [...] background or padding area of the element" has been corrected to
Even if the image is fixed, it is still only visible when it is in the background, padding or border area of the element.
In bullet 2, changed "the UA uses the 'font-family' descriptor" to "the UA uses the 'font-family' property".
The statement "Negative values are not allowed" for 'font-size' now applies to percentages as well as lengths.
Corrected 'text-indent' to apply to table cells (and inline blocks) as well as block-level elements.
Corrected 'text-align' to apply to table cells (and inline blocks) as well as block-level elements.
Changed prose about the effect of 'justify' to be less correct.
Corrected the note to say that justification is also dependent on the script, not just the language, of the text.
In the definition of table-header-group, changed "footer" to "header" in "Print user agents may repeat footer rows on each page spanned by a table."
Added 'table-header-group' and 'table-footer-group' alongside mentions of 'table-row-group' where missing.
Corrected 'caption' to 'table-caption'.
Added missing rule (#3) for 'table-column' boxes.
Added 'table-caption' and 'table-column-group' to list of boxes requiring a 'table' or 'inline-table' parent in rule 4.
Added rules 5 and 6 to generate 'table-row' boxes where necessary for children of 'table'/'inline-table' and 'table-row-group'/'table-header-group'/'table-footer-group' boxes.
Specified handling of multiple caption boxes.
Specified that the anonymous outer table box is a 'block' box if the table is block-level and an 'inline-block' box if the table is inline-level but that the anonymous outer table box cannot accept run-ins.
Correct text that said all internal table elements have padding; change to say that of these only table cells have padding.
The following note:
Note. Table cells may be relatively and absolutely positioned, but this is not recommended: positioning and floating remove a box from the flow, affecting table alignment.
has been amended as follows:
Note. Table cells may be positioned, but this is not recommended: absolute and fixed positioning, as well as floating, remove a box from the flow, affecting table size.
The rows and columns only cover the whole table in the collapsed borders model, not in the separated borders model.
The points 2, 3, 4 and 5 have been corrected to define the area covered by rows, columns, row groups and column groups and thus the positioning and painting of backgrounds on those elements.
Specify the handling of "missing cells".
In the image, changed "cell-spacing" to "border-spacing".
For the 'ButtonHighlight' value, changed the description from "Dark shadow" to "Highlight color".
Changed "but any descendants which actually create a new stacking
context" to "but any positioned descendants and descendants
which actually create a new stacking context" (3 times).
This change also occurred once in section 9.5 (Floats) and once in
section section 9.9 (Layered
presentation).
This section has been marked non-normative. This section has been marked non-normative. Added a statement about case-sensitivity of selectors for XML. The specification for the XML
style sheet PI
was written after CSS2 was finalized. The first line of the full XML
example should not have been be This section has been marked non-normative.
Added a note to clarify that the deprecated/non-deprecated status
of a feature is distinct from its normative/non-normative status. Under 'document language' clarified that CSS only describes the
presentation of a document language, and has no effect on its semantics. Changed definition of 'replaced element' to "an element whose content
is outside the scope of the CSS formatting model" and added further clarifying
text. This clarifies that e.g. SVG images embedded in an XML document are
also considered replaced elements, not just those linked in from an outside
file. Also changed definition of 'rendered content' to be consistent with this
clarification. Added under "Intrinsic dimension" that raster images without
reliable resolution information are assumed to have a size of 1&nbpspx
unit per image source pixel.
Added definition for 'ignore'. Added definition for 'HTML user agent'. Added definition for 'property'. Moved definitions of "immediately before" and "immediately after" forward
so they apply to the whole Syntax section. Added sections 4.1.2.1 and 4.1.2.2 to defined vendor-specific
extensions. Clarified that input that cannot be parsed according to the core syntax
is ignored according to the rules for handling parsing errors. Clarified that input that cannot be tokenized or parsed has no meaning in
CSS2.1. Clarified that when a CRLF pair terminates an escape sequence, the pair
is treated as a single white space character as corrected
in the tokenization rules. Replaced "[a-z0-9]" by "[a-zA-Z0-9]" as an extra reminder that CSS
identifiers are case-insensitive.
Replaced the term "{}-block" with "declaration block". Clarified that all property:value combinations and @-keywords that do not
contain an identifier beginning with dash or underscore are reserved by CSS
for future use. Clarified that when something inside an at-rule is ignored because it is
invalid, this does not make the entire at-rule invalid. Referenced section 4.1.7 for parsing invalid bits inside declaration
blocks. Clarified that '-0' is equivalent to '0' and is not a negative number. Clarified that negative length values on properties that don't allow them
cause the declaration to be ignored. Reduced unnecessary discussion of what a URI is. Added note about terminology change ("simple selector") between
CSS2 and CSS3.
Clarified that text nodes and comments do not affect whether a
sibling selector matches.
Clarified ~= and |= by using the definitions from the Selectors
module.
Clarified that rules about default attribute values are the same,
whether the default is specified in a DTD or by other means.
Added a note that it depends on the document format which
attributes are ID attributes.
Clarified that CSS 2.1 does not define if the parent
of an element that matches ':active' or ':hover' itself also matches
':active' or ':hover'.
Added note that, in CSS1, ':active' only applies to links.
Added a note to show the differences between ':lang(xx)' and
'[lang=xx]'.
Clarified that digits can also be first letter.
Clarified that computed values are inherited (not specified values)
and that they become the specified value on the inheritor. Removed discussion of "default" styles for a document. Clarify that 'inherit' can be used on properties that are not normally inherited
and that when set on the root element, it has the effect of assigning the
property's initial value. Except @charset from the statement that @imports must precede all other rules. Obfuscated note about system settings and UA limitations. Various editorial changes to clarify sort order. Added a note:
The specificity is based only on the form of the selector.
In particular, a selector of the form " Clarify that Style rules outside of @media rules apply to the same
media types that the style sheet itself applies to. Added text to clarify that media types are mutually exclusive,
but a UA can render simulatenously to canvases with different
media types. Split "aural" media group into "audio" and "speech". The background style of the content, padding, and border areas of a
box is specified by the 'background' property of the
generating element. Margin backgrounds are always transparent.
Added a sentence to note that vertical margins have no effect on non-replaced
inline elements. Changed "absolute maximum" to "maximum of the absolute values" in
sentence about negative margins collapsing. Added this clarifying note to the first bullet of the explanation
of vertical collapsing of margins: Note. Adjoining boxes may be generated by
elements that are not related as siblings or ancestors.
Emphasized that floating elements' margins do not collapse even between a float
and its in-flow children. Emphasized that absolutely positioned elements' margins do not collapse even between
the positioned element and its in-flow children. Changed description of 'none' value to not imply that all four border
widths are set to zero. Changed the sentence "When the viewport is smaller than the ..., the user
agent should offer a scrolling mechanism" to use "area of the canvas on
which the document is rendered" instead of "document's initial containing
block". Clarified that 'display: none' also applies to non-visual media.
Clarified that the margins of fixed positioned boxes do not collapse
with any other margins. Clarified that in print media fixed boxes are rendered on every page. Clarified that negative lengths and percentages are allowed as values
of 'top', 'right', 'bottom', and 'left'. Added "For replaced elements, the effect of this value depends only
on the intrinsic dimensions of the replaced content. See the sections
on the width and height of absolutely positioned, replaced elements
for details." to the definition of 'auto' because that's not what
chapter 10 says at all. Clarified that 'justify' stretches "spaces and words in inline boxes";
previous text simply said that it stretches "inline boxes". The statement "When an inline box is split, margins, borders, and
padding have no visual effect where the split occurs." has been
generalized. Margins, borders, and padding have no visual effect
where one or more splits occur. Clarified that an inline box that exceeds the width of a line box
and cannot be split therefore overflows the line box. Removed sentence about formatting of margins, borders, and padding
for split inline boxes not being fully defined when affected by bidi
as that situation is now defined in section
8.6. Clarified that although relative positioning normally doesn't
directly affect layout, it may affect layout indirectly through
the creation of scrollbars. Relatively positioned boxes do not always establish new containing
blocks. Changed the second paragraph to refer to the section on
containing blocks accordingly. The paragraph about dynamic movement and superscripting has been
shifted into a non-normative note. Clarified that line boxes are shortened to make room for the
margin box of the float. Added some text to clarify what "Any content in the current line before
a floated box is reflowed in the first available line on the other side of
the float" means. Clarified floats' position in the stacking order. Clarified that the elements referenced in the float behavior
rules are in the same block formatting context as the float. Clarified that the effects of 'clear' do not consider floats
in other block formatting contexts. Added a note to clarify that the images in this section are not
drawn to scale and are illustrations, not reference renderings. Noted that a containing block formed by inline elements may wind up
with a negative containing block width. In the definition of <length> values for the 'width' property,
changed "Specifies a fixed width" to "Specifies the width of the content
area using a length unit". Clarified that setting both left and right margins to 'auto'
horizontally centers the element within its containing block. Clarified which part of the text of section 10.3.7 is re-used.
Clarified that 'min-width' and 'max-width' do not affect the
computed values of any properties. (They only affect the used value.) Clarified that these rules apply to the root element just as to
any other element. Clarified that 'min-width' and 'max-width' do not affect the
computed values of any properties. (They only affect the used value.) Removed clarifying note about line height being taller than tallest
single inline box due to vertical alignment. Removed "slightly" from the note "Values of this property have
Clarified when absolute positioning and negative margins cause
overflow. Added 'text-indent' to the list of things that can cause overflow. Removed mention of 'clip' since it no longer affects most elements;
mentioned that the 'overflow' property also specifies whether a
scrolling mechanism is provided to access clipped content. Clarified that descendant elements whose containing block is the
viewport or an ancestor of the element are not affected by overflow
clipping. Removed unnecessary mentions of the 'clip' property from the 'hidden'
value definition. Changed "portion of an element's rendered content" to "portion
of an element's border box" since clipping also affects the element's
backgrounds and borders. Clarified what parts of the element are affected by clipping. Clarified that clipped content does not cause overflow. Clarified that arguments of clip() can be separated by spaces or by
commas, but not a combination.
Clarified that descendants of a 'visibility: hidden' element will
be visible if they have 'visibility: visible'. Clarified that :before and :after pseudo-elements interact with
other boxes as if they were real elements just inside their associated
element.
Noted that the interaction of :before and :after with replaced elements
is left undefined for now. Clarified which counters are used for counter() and counters() in
case there are multiple counters of the same name. Removed note about common typographic practices when quotes in
different languages are mixed. In the "self-nesting" behavior of counters, clarified that merely
using a counter in a child element doesn't create a new instance of it:
only resetting it does. Clarified that the scope of a counter does not include any elements
in the scope of a counter with the same name created by a 'counter-reset'
on a later sibling or a later 'counter-reset' on the same element. Removed sentence about scope of 'counter-increment' without prior
'counter-reset' as that is now defined (differently) under
"12.4.1 Nested counters and scope." Clarified that pseudo-elements that generate no boxes also do not
increment counters.
Clarified that the root background image, although painted over the entire
canvas, is anchored as if painted only for the root element, and that the root's
background is only painted once. Clarified rules for propagation of background settings on HTML's <body>
element to the root. Added statement about z-index of backgrounds for elements that form a
stacking context and referred to z-index property for details. Added this note after the first paragraph after 'background-attachment':
Note that there is only one viewport per
document. I.e., even if an element has a scrolling mechanism (see
'overflow'), a 'fixed' background doesn't move with it. Definition of 'background-position' has been rewritten as normative rules
rather than just examples. Stated that the tiling and positioning of background images for inline
elements is undefined in CSS2.1. Drastically shortened introduction. In the per-property rule 2, clarified that 'normal' matches
the non-small-caps variant (if there is one). Removed discussion of font-matching algorithm. (It is already
covered in the font-matching algorithm's
own section. Clarified that quoted strings that are the same as a keyword
value must be treated as font family names and not as the keyword
value (which must be unquoted). This section, previously section 15.2.6, has been moved but no
other change was made. The text for this section (formerly part of 15.2.3) has been
reverted to its CSS1 format. The text for this section (formerly part of 15.2.3) has been
reverted to its CSS1 format. Clarified that CSS2.1 cannot select font variants besides small-caps. Clarified that when "font-variant: small-caps" results in the
substitution of full-caps, the behavior is the same as for
text-transform. The text for this section (formerly part of 15.2.3) has been
reverted to its CSS1 format. Also, discussion of font-weight from
other parts of the Fonts chapter has been aggregated under this
section. Removed statemnt that says "User agents must map names to values
in a way that preserves visual order; a face mapped to a value
must not be lighter than faces mapped to lower values." This is
otherwise implied by "The only guarantee is that a face of a given
value will be no less dark than the faces of lighter values." Clarified relationship of font size to em squares. Added a totally irrelevant note about font sizes virtual reality
scenes. Clarified that text overflowing due to text-indent is affected
by the 'overflow' property. Added a note about text-indents inheriting behavior and suggesting
'text-indent: 0' on inline-blocks. Changed "double justify" to "justify" under "left, right, center,
and justify". Added an example to illustrate how underlining affects descendant
boxes. Switched language reference from RFC2070 to RFC3066. Added section 16.6.1 as an example
to illustrate the interaction of white space collapsing and bidi. Expanded introduction to include a brief discussion of the two
table layout models. Mentioned that the automatic table algorithm
is not fully defined in CSS 2.1 but that some implementations
have achieved relatively close interoperability. Clarify that all table captions must be rendered if more than
one exists. Specified that replaced elements with table display values are
treated as table elements in table layout. Moved the first bullet text to the prose before the list of
generation rules as it is a general statement of what the rules
are supposed to accomplish. Clarified that "display: table" elements behave as block-level elements
and "display: inline-table" elements behave as inline-level elements and
not the other way around. Clarified that 'table-caption' boxes behave as normal block boxes
within the outer anonymous table box. Clarified that percentage 'width' and 'height' on the table box is
relative to the anonymous box's containing block, not the anonymous
box itself.
Clarified that the 'position', 'float', 'top', 'right', 'bottom',
and 'left' values on the table box are used on the anonymous outer
box instead of the To remove ambiguity about the position of extent of internal
table boxes, the following paragraph was the edges of the Changed warning note about positioning of table cells to be more
precise about the At the end of Note that if the table has Added a paragraph to clarify the interaction of the table width
algorithms with the rules in
Explicitly mentioned that the fixed table layout algorithm may be
used with the algorithm of section
10.3.3 when 'table-layout' is 'fixed' but 'width' is 'auto'. Clarified that UAs can use other algorithms besides the one in
Changed "The horizontal alignment of a cell's content within a cell
box is specified with the 'text-align' property" to "The horizontal
alignment of a cell's inline content within a cell box
can be specified with Clarified that not Added a note explaining that 'border-spacing' can be used as a
substitute for the Added clarification about backgrounds: the
sentence "This space is filled with the background of the In this space, the In the Noted that system colors are deprecated in Clarified that outlines do not Clarified that outlines are only fully connected "if possible". Clarify that changing outlines in Added paragraph clarifying that some presentational markup in
In addition to lowercasing all HTML tag names, the following changes
were made:C.4 Clarifications
C.4.1 Section 2.1
A brief CSS 2.1 tutorial for HTML
C.4.2 Section 2.2
A brief CSS 2.1 tutorial for XML
<?XML:stylesheet type="text/css"
href="bach.css"?>, but
<?xml-stylesheet type="text/css" href="bach.css"?>
C.4.3 Section 2.3
The CSS 2.1 processing model
C.4.4 Section 3.1
Definitions
C.4.5 Section 4.1
Syntax
C.4.6 Section 4.1.1
Tokenization
C.4.7 Section 4.1.3
Characters and case
C.4.8 Section 4.1.7
Rule sets, declaration blocks, and selectors
C.4.9 Section 4.2
Rules for handling parsing errors
C.4.10 Section 4.3.1
Integers and real numbers
C.4.11 Section 4.3.2
Lengths
C.4.12 Section 4.3.4
URLs and URIs
C.4.13 Section 5.1
Pattern matching
C.4.14 Section 5.7
Adjacent sibling selectors
C.4.15 Section 5.8.1
Matching attributes and attribute values
C.4.16 Section 5.8.2
Default attribute values in DTDs
C.4.17 Section 5.9 ID
selectors
C.4.18 Section 5.11.3 The
dynamic pseudo-classes: :hover, :active, and :focus
C.4.19 Section 5.11.4 The
language pseudo-class: :lang
C.4.20 Section 5.12.2
The :first-letter pseudo-element
C.4.21 Section 6.2 Inheritance
C.4.22 Section 6.2.1 The 'inherit' value
C.4.23 Section 6.3 The @import rule
C.4.24 6.4 The Cascade
C.4.25 6.4.1 Cascading order
C.4.26 Section 6.4.3 Calculating a
selector's specificity
[id=p33]" is
counted as an attribute selector (a=0, b=1, c=0), even if the
id attribute is defined as an "ID" in the source
document's DTD.
C.4.27 Section 7.2.1
The @media rule
C.4.28 Section 7.3 Recognized
media types
C.4.29 Section 7.3.1
Media groups
C.4.30 Section 8.1 Box dimensions
C.4.31 Section 8.3 Margin properties
C.4.32 Section 8.3.1
C.4.33 Section 8.5.3
Border style
C.4.34 Section 9.1.1
The viewport
C.4.35 9.2.4 The
'display' property
C.4.36 Section 9.3.1
Choosing a positioning scheme
C.4.37 Section 9.3.2
Box offsets
C.4.38 Section 9.4.2
Inline formatting context
C.4.39 Section 9.4.3
Relative positioning
C.4.40 Section 9.5
Floats
C.4.41 Section 9.5.1
Positioning the float
C.4.42 Section 9.5.2
Controlling flow next to floats
C.4.43 Section 9.8
Comparison of normal flow, floats, and absolute positioning
C.4.44 Section 10.1
Definition of "containing block"
C.4.45 Section 10.2
Content width
C.4.46 Section 10.3.3
Block-level, non-replaced elements in normal flow
C.4.47 Section 10.3.8
Absolutely positioning, replaced elements
C.4.48 Section 10.4
Minimum and maximum widths
C.4.49 Section 10.6
Calculating heights and margins
C.4.50 Section 10.7
Minimum and maximum heights
C.4.51 Section 10.8
Line height calculations
C.4.52 Section 10.8.1 Leading
and half-leading
slightly different meanings in the context of tables."
C.4.53 Section 11.1
Overflow and clipping
C.4.54 Section 11.1.1
Overflow
C.4.55 Section 11.1.2
Clipping
C.4.56 Section 11.2
Visibility
C.4.57 Section 12.1
The :before and :after pseudo-elements
C.4.58 Section 12.2
The 'content' property
C.4.59 Section 12.3.2
Inserting quotes with the 'content' property
C.4.60 Section 12.4
Automatic counters and numbering
C.4.61 Section 12.4.3
Counters in elements with 'display: none'
C.4.62 Section 14.2 The background
C.4.63 Section 15.1 Fonts Introduction
C.4.64 Section 15.2
Font matching algorithm
C.4.65 Section 15.2.2 Font family
C.4.66 Section 15.3.1
Generic font families
C.4.67 Section 15.4
Font styling
C.4.68 Section 15.5
Small-caps
C.4.69 Section 15.6
Font boldness
C.4.70 Section 15.7
Font size
C.4.71 Section 16.1
Indentation
C.4.72 16.2
Alignment
C.4.73 Section 16.3.1
Underlining, over lining, striking, and blinking
C.4.74 Section 16.5
Capitalization
C.4.75 Section 16.6
White space
C.4.76 Section 17.1
Introduction to tables
C.4.77 Section 17.2
The CSS table model
C.4.78 Section 17.2.1
Anonymous table objects
C.4.79 Section 17.4
Tables in the visual formatting model
new 'text-shadow' property. Several new pseudo-classes , :first-child, :hover, :focus, :lang. System colorstable box and fonts . Cursors . Dynamic outlines . B.2 Updated descriptionsthat the CSS1 specificationtable box itself uses the
initial values of those properties.C.4.80 Section 17.5
Visual layout of table contents
short and concise. This specification is much more voluminous and more readable. Muchadded after point 6:
additional content describes new functionality, butrows, columns, row groups and column
groups in the descriptioncollapsing borders
model coincide with the hypothetical grid lines on which the
borders of CSS1 features has also been extended. Exceptthe cells are centered. (And thus, in a few cases described below,this model, the rewritten descriptions do not indicate a changerows
together exactly cover the table, leaving no gaps; ditto for the
columns.) In syntax nor semantics. B.3 Semantic changes from CSS1 While all CSS1 style sheets are valid CSS2 style sheets,the separated borders
model, the edges coincide with the border edges of cells. (And thus, in
this model, there are a few cases wheremay be gaps between the CSS1 style sheet will have a different meaning when interpreted as a CSS2 style sheet. Most changes are duerows and columns,
corresponding to implementation experience feeding back intothe specification, but there are also some error corrections.'border-spacing'
property.)meaningpossibly unintended effects.C.4.81 Section 17.5.1 Table layers and
transparency
"!important"the section added the following paragraph:
been changed. In CSS1, "!important"'border-collapse: separate',
the background of the area given by the 'border-spacing' property is
always the background of the table element. See 17.6.1C.4.82 Section 17.5.2 Table width algorithms
an author's style sheet took precedence oversection 10.3
(Calculating widths and margins).C.4.83 Section 17.5.2.1
Fixed table layout
C.4.84 Section 17.5.2.2
Automatic table layout
a user style sheet.this has been reversedsection even if it results in CSS2.different behavior.
Also marked the rest of the section non-normative in CSS2 color values are clippedaccordance
with that statement.C.4.85 Section 17.5.4
Horizontal alignment in a column
regard tothe device gamut,'text-align' property."
C.4.86 Section 17.5.5
Dynamic row and column effects
with regard to the sRGB gamut as in CSS1. CSS1 simply saidaffecting layout means that 'margin-right' was ignored if'visibility: collapse'
causes the both 'margin-left'part of row- and 'width' were set. In CSS2 the choice between relaxing 'margin-right' or 'margin-left' depends oncolumn-spanning cells that span into
the writing direction. In CSS1, several properties (e.g., 'padding') had values referringcollapsed row to be clipped.C.4.87 17.6.1
The separated borders model
widthnon-standard 'framespacing' attribute on
frameset elements (which are out-of-scope for CSS2.1).parent element. Thistable
element" was an error;replaced by:
value should always referrow, column, row group, and column
group backgrounds are invisible, allowing the table background to show
through.C.4.88 Section 17.6.2
The
width of a block-level element and this specification reflects this by introducingcollapsing borders modelterm "containing block".sentence after the initial valuequestion, added "and
padding-lefti and padding-righti refer
to the left (resp., right) padding of 'display' is 'inline'cell i."
C.4.89 Section 18.2
System Colors
CSS2,CSS3.C.4.90 Section 18.4
Dynamic outlines
'block' as in CSS1. In CSS1, the 'clear' property applied to all elements. This was an error,cause overflow.C.4.91 Section 18.4.1
Outlines and the
property only applies to block-level elements in CSS2.focusCSS1, ':link' , ':visited' and ':active' were mutually exclusive;response to focus
should not cause a document to reflow.C.4.92 Appendix D
CSS2, ':active'HTML can occur togetherbe replaced with ':link' or ':visited' . The suggested scaling factor between adjacent 'font-size' indexesCSS, but it requires different markup.C.5 Code Diffs for Appendices D and G
C.5.1 Appendix D
Default style sheet for HTML4
-ADDRESS,
+html, address,
BLOCKQUOTE,
BODY, DD, DIV,
-DL, DT,
-FIELDSET, FORM,
+dl, dt, fieldset, form,
FRAME, FRAMESET,
-H1, H2, H3, H4,
-H5, H6, IFRAME,
-NOFRAMES,
+h1, h2, h3, h4,
+h5, h6, noframes,
-OBJECT, OL, P,
-UL, APPLET,
-CENTER, DIR,
-HR, MENU, PRE { display: block }
+ol, p, ul, center,
+dir, hr, menu, pre { display: block }
LI { display: list-item }
HEAD { display: none }
TABLE { display: table }
TR { display: table-row }
THEAD { display: table-header-group }
TBODY { display: table-row-group }
TFOOT { display: table-footer-group }
COL { display: table-column }
COLGROUP { display: table-column-group }
TD, TH { display: table-cell }
CAPTION { display: table-caption }
TH { font-weight: bolder; text-align: center }
CAPTION { text-align: center }
-BODY { padding: 8px; line-height: 1.33 }
+body { margin: 8px }
H1 { font-size: 2em; margin: .67em 0 }
-H2 { font-size: 1.5em; margin: .83em 0 }
-H3 { font-size: 1.17em; margin: 1em 0 }
+h2 { font-size: 1.5em; margin: .75em 0 }
+h3 { font-size: 1.17em; margin: .83em 0 }
H4, P,
BLOCKQUOTE, UL,
FIELDSET, FORM,
OL, DL, DIR,
-MENU { margin: 1.33em 0 }
-H5 { font-size: .83em; line-height: 1.17em; margin: 1.67em 0 }
-H6 { font-size: .67em; margin: 2.33em 0 }
+menu { margin: 1.12em 0 }
+h5 { font-size: .83em; margin: 1.5em 0 }
+h6 { font-size: .75em; margin: 1.67em 0 }
H1, H2, H3, H4,
H5, H6, B,
STRONG { font-weight: bolder }
BLOCKQUOTE { margin-left: 40px; margin-right: 40px }
I, CITE, EM,
VAR, ADDRESS { font-style: italic }
PRE, TT, CODE,
KBD, SAMP { font-family: monospace }
PRE { white-space: pre }
+button, textarea,
+input, select { display: inline-block }
BIG { font-size: 1.17em }
SMALL, SUB, SUP { font-size: .83em }
SUB { vertical-align: sub }
SUP { vertical-align: super }
+table { border-spacing: 2px; }
+thead, tbody,
+tfoot { vertical-align: middle }
+td, th { vertical-align: inherit }
S, STRIKE, DEL { text-decoration: line-through }
HR { border: 1px inset }
OL, UL, DIR,
MENU, DD { margin-left: 40px }
OL { list-style-type: decimal }
OL UL, UL OL,
UL UL, OL OL { margin-top: 0; margin-bottom: 0 }
U, INS { text-decoration: underline }
-CENTER { text-align: center }
BR:before { content: "\A" }
-
-/* An example of
font sizes has been reduced from 1.5 to 1.2. The computed value,style for HTML 4.0's ABBR/ACRONYM elements */
-
-ABBR, ACRONYM { font-variant: small-caps; letter-spacing: 0.1em }
-A[href] { text-decoration: underline }
+:before, :after { white-space: pre-line }
+center { text-align: center }
+:link, :visited { text-decoration: underline }
:focus { outline: thin dotted invert }
-/* Begin bidirectionality settings (do not the actual value, of 'font-size' is inherited. The CSS1 description of 'inside' (for 'list-style-position' ) allowed the interpretationchange) */
+/* Begin bidirectionality settings (do not change) */
BDO[DIR="ltr"] { direction: ltr; unicode-bidi: bidi-override }
BDO[DIR="rtl"] { direction: rtl; unicode-bidi: bidi-override }
*[DIR="ltr"] { direction: ltr; unicode-bidi: embed }
*[DIR="rtl"] { direction: rtl; unicode-bidi: embed }
-
-/* Elements that the left margin of the text was affected, rather than the position of the bullet.are block-level in CSS2 that interpretation is ruled out. Please also consult the normativeHTML4 */
-ADDRESS, BLOCKQUOTE, BODY, DD, DIV, DL, DT, FIELDSET,
-FORM, FRAME, FRAMESET, H1, H2, H3, H4, H5, H6, IFRAME,
-NOSCRIPT, NOFRAMES, OBJECT, OL, P, UL, APPLET, CENTER,
-DIR, HR, MENU, PRE, LI, TABLE, TR, THEAD, TBODY, TFOOT,
-COL, COLGROUP, TD, TH, CAPTION
- { unicode-bidi: embed }
-/* End bidi settings */
@media print {
- @page { margin: 10% }
+ h1 { page-break-before: always }
H1, H2, H3,
- H4, H5, H6 { page-break-after: avoid; page-break-inside: avoid }
+ h4, h5, h6 { page-break-after: avoid }
- BLOCKQUOTE,
- PRE { page-break-inside: avoid }
UL, OL, DL { page-break-before: avoid }
}
-@media speech {
- H1, H2, H3,
- H4, H5, H6 { voice-family: paul, male; stress: 20; richness: 90 }
- H1 { pitch: x-low; pitch-range: 90 }
- H2 { pitch: x-low; pitch-range: 80 }
- H3 { pitch: low; pitch-range: 70 }
- H4 { pitch: medium; pitch-range: 60 }
- H5 { pitch: medium; pitch-range: 50 }
- H6 { pitch: medium; pitch-range: 40 }
- LI, DT, DD { pitch: medium; richness: 60 }
- DT { stress: 80 }
- PRE, CODE, TT { pitch: medium; pitch-range: 0; stress: 0; richness: 80 }
- EM { pitch: medium; pitch-range: 60; stress: 60; richness: 50 }
- STRONG { pitch: medium; pitch-range: 60; stress: 90; richness: 90 }
- DFN { pitch: high; pitch-range: 60; stress: 60 }
- S, STRIKE { richness: 0 }
- I { pitch: medium; pitch-range: 60; stress: 60; richness: 50 }
- B { pitch: medium; pitch-range: 60; stress: 90; richness: 90 }
- U { richness: 0 }
- A:link { voice-family: harry, male }
- A:visited { voice-family: betty, female }
- A:active { voice-family: betty, female; pitch-range: 80; pitch: x-high }
-}
C.5.2 Section
on the differences between the CSS1 and CSS2 tokenizerG.1
Grammar
stylesheet
- : [ CHARSET_SYM S* STRING S* ';' ]?
+ : [ CHARSET_SYM STRING ';' ]?
[S|CDO|CDC]* [ import [S|CDO|CDC]* ]*
- [ [ ruleset | media | page | font_face ] [S|CDO|CDC]* ]*
+ [ [ ruleset | media | page ] [S|CDO|CDC]* ]*
;
import
: IMPORT_SYM S*
- [STRING|URI] S* [ medium [ ',' S* medium]* ]? ';' S*
+ [STRING|URI] S* [ medium [ COMMA S* medium]* ]? ';' S*
;
media
- : MEDIA_SYM S* medium [ ',' S* medium ]* '{' S* ruleset* '}' S*
+ : MEDIA_SYM S* medium [ COMMA S* medium ]* LBRACE S* ruleset* '}' S*
;
medium
: IDENT S*
;
page
- : PAGE_SYM S* IDENT? pseudo_page? S*
- '{' S* declaration [ ';' S* declaration ]* '}' S*
+ : PAGE_SYM S* pseudo_page? S*
+ LBRACE S* declaration [ ';' S* declaration ]* '}' S*
;
pseudo_page
: ':' IDENT
;
-font_face
- : FONT_FACE_SYM S*
- '{' S* declaration [ ';' S* declaration ]* '}' S*
- ;
operator
- : '/' S* | ',' S* | /* empty */
+ : '/' S* | COMMA S* | /* empty */
;
combinator
- : '+' S* | '>' S* | /* empty */
+ : PLUS S*
+ | GREATER S*
+ | S
;
unary_operator
- : '-' | '+'
+ : '-' | PLUS
;
property
: IDENT S*
;
ruleset
- : selector [ ',' S* selector ]*
- '{' S* declaration [ ';' S* declaration ]* '}' S*
+ : selector [ COMMA S* selector ]*
+ LBRACE S* declaration [ ';' S* declaration ]* '}' S*
;
selector
: simple_selector [ combinator simple_selector ]*
;
-/*
- * simple selector cannot start with attrib selector
- */
simple_selector
- : element_name [ HASH | class | attrib | pseudo ]* S*
- | HASH [ HASH | class | attrib | pseudo ]* S*
- | pseudo [ HASH | class | attrib | pseudo ]* S*
- | class [ HASH | class | attrib | pseudo ]* S*
+ : element_name [ HASH | class | attrib | pseudo ]*
+ | [ HASH | class | attrib | pseudo ]+
;
class
: '.' IDENT
@@ -108,7 +98,7 @@
[ IDENT | STRING ] S* ]? ']'
;
pseudo
- : ':' [ IDENT | FUNCTION S* IDENT S* ')' ]
+ : ':' [ IDENT | FUNCTION S* IDENT? S* ')' ]
;
declaration
: property ':' S* expr prio?
| /* empty */
;
prio
: IMPORTANT_SYM S*
;
expr
: term [ operator term ]*
;
term
: unary_operator?
[ NUMBER S* | PERCENTAGE S* | LENGTH S* | EMS S* | EXS S* | ANGLE S* |
- TIME S* | FREQ S* | function ]
- | STRING S* | IDENT S* | URI S* | RGB S* | UNICODERANGE S* | hexcolor
+ TIME S* | FREQ S* ]
+ | STRING S* | IDENT S* | URI S* | hexcolor | function
;
function
: FUNCTION S* expr ')' S*
C.5.3 Section G.2
Lexical scanner
%option case-insensitive
h [0-9a-f]
nonascii [\200-\377]
-unicode \\{h}{1,6}[ \t\r\n\f]?
+unicode \\{h}{1,6}(\r\n|[ \t\r\n\f])?
-escape {unicode}|\\[ -~\200-\377]
+escape {unicode}|\\[^\r\n\f0-9a-f]
-nmstart [a-z]|{nonascii}|{escape}
-nmchar [a-z0-9-]|{nonascii}|{escape}
+nmstart [_a-z]|{nonascii}|{escape}
+nmchar [_a-z0-9-]|{nonascii}|{escape}
-string1 \"([\t !#$%&(-~]|\\{nl}|\'|{nonascii}|{escape})*\"
-string2 \'([\t !#$%&(-~]|\\{nl}|\"|{nonascii}|{escape})*\'
+string1 \"([^\n\r\f\\"]|\\{nl}|{escape})*\"
+string2 \'([^\n\r\f\\']|\\{nl}|{escape})*\'
+invalid1 \"([^\n\r\f\\"]|\\{nl}|{escape})*
+invalid2 \'([^\n\r\f\\']|\\{nl}|{escape})*
+comment \/\*[^*]*\*+([^/*][^*]*\*+)*\/
-ident {nmstart}{nmchar}*
+ident -?{nmstart}{nmchar}*
name {nmchar}+
num [0-9]+|[0-9]*"."[0-9]+
string {string1}|{string2}
+invalid {invalid1}|{invalid2}
url ([!#$%&*-~]|{nonascii}|{escape})*
-w [ \t\r\n\f]*
+s [ \t\r\n\f]+
+w {s}?
nl \n|\r\n|\r|\f
-range \?{1,6}|{h}(\?{0,5}|{h}(\?{0,4}|{h}(\?{0,3}|{h}(\?{0,2}|{h}(\??|{h})))))
+
+A a|\\0{0,4}(41|61)(\r\n|[ \t\r\n\f])?
+C c|\\0{0,4}(43|63)(\r\n|[ \t\r\n\f])?
+D d|\\0{0,4}(44|64)(\r\n|[ \t\r\n\f])?
+E e|\\0{0,4}(45|65)(\r\n|[ \t\r\n\f])?
+G g|\\0{0,4}(47|67)(\r\n|[ \t\r\n\f])?|\\g
+H h|\\0{0,4}(48|68)(\r\n|[ \t\r\n\f])?|\\h
+I i|\\0{0,4}(49|69)(\r\n|[ \t\r\n\f])?|\\i
+K k|\\0{0,4}(4b|6b)(\r\n|[ \t\r\n\f])?|\\k
+M m|\\0{0,4}(4d|6d)(\r\n|[ \t\r\n\f])?|\\m
+N n|\\0{0,4}(4e|6e)(\r\n|[ \t\r\n\f])?|\\n
+O o|\\0{0,4}(51|71)(\r\n|[ \t\r\n\f])?|\\o
+P p|\\0{0,4}(50|70)(\r\n|[ \t\r\n\f])?|\\p
+R r|\\0{0,4}(52|72)(\r\n|[ \t\r\n\f])?|\\r
+S s|\\0{0,4}(53|73)(\r\n|[ \t\r\n\f])?|\\s
+T t|\\0{0,4}(54|74)(\r\n|[ \t\r\n\f])?|\\t
+X x|\\0{0,4}(58|78)(\r\n|[ \t\r\n\f])?|\\x
+Z z|\\0{0,4}(5a|7a)(\r\n|[ \t\r\n\f])?|\\z
%%
-[ \t\r\n\f]+ {return S;}
+{s} {return S;}
-\/\*[^*]*\*+([^/][^*]*\*+)*\/ /* ignore comments */
+\/\*[^*]*\*+([^/*][^*]*\*+)*\/ /* ignore comments */
+{s}+\/\*[^*]*\*+([^/*][^*]*\*+)*\/ {unput(' '); /*replace by space*/}
-"<!--" {return CDO;}
+"<!--" {return CDO;}
"-->" {return CDC;}
"~=" {return INCLUDES;}
"|=" {return DASHMATCH;}
+{w}"{" {return LBRACE;}
+{w}"+" {return PLUS;}
+{w}">" {return GREATER;}
+{w}"," {return COMMA;}
+
{string} {return STRING;}
+{invalid} {return INVALID; /* unclosed string */}
{ident} {return IDENT;}
"#"{name} {return HASH;}
-"@import" {return IMPORT_SYM;}
-"@page" {return PAGE_SYM;}
-"@media" {return MEDIA_SYM;}
-"@font-face" {return FONT_FACE_SYM;}
-"@charset" {return CHARSET_SYM;}
-"@"{ident} {return ATKEYWORD;}
+@{I}{M}{P}{O}{R}{T} {return IMPORT_SYM;}
+@{P}{A}{G}{E} {return PAGE_SYM;}
+@{M}{E}{D}{I}{A} {return MEDIA_SYM;}
+@{C}{H}{A}{R}{S}{E}{T} {return CHARSET_SYM;}
-"!{w}important" {return IMPORTANT_SYM;}
+"!"({w}|{comment})*{I}{M}{P}{O}{R}{T}{A}{N}{T} {return IMPORTANT_SYM;}
-{num}em {return EMS;}
-{num}ex {return EXS;}
-{num}px {return LENGTH;}
-{num}cm {return LENGTH;}
-{num}mm {return LENGTH;}
-{num}in {return LENGTH;}
-{num}pt {return LENGTH;}
-{num}pc {return LENGTH;}
-{num}deg {return ANGLE;}
-{num}rad {return ANGLE;}
-{num}grad {return ANGLE;}
-{num}ms {return TIME;}
-{num}s {return TIME;}
-{num}Hz {return FREQ;}
-{num}kHz {return FREQ;}
-{num}{ident} {return DIMEN;}
+{num}{E}{M} {return EMS;}
+{num}{E}{X} {return EXS;}
+{num}{P}{X} {return LENGTH;}
+{num}{C}{M} {return LENGTH;}
+{num}{M}{M} {return LENGTH;}
+{num}{I}{N} {return LENGTH;}
+{num}{P}{T} {return LENGTH;}
+{num}{P}{C} {return LENGTH;}
+{num}{D}{E}{G} {return ANGLE;}
+{num}{R}{A}{D} {return ANGLE;}
+{num}{G}{R}{A}{D} {return ANGLE;}
+{num}{M}{S} {return TIME;}
+{num}{S} {return TIME;}
+{num}{H}{Z} {return FREQ;}
+{num}{K}{H}{Z} {return FREQ;}
+{num}{ident} {return DIMENSION;}
{num}% {return PERCENTAGE;}
{num} {return NUMBER;}
-"url("{w}{string}{w}")" {return URI;}
-"url("{w}{url}{w}")" {return URI;}
+{U}{R}{L}("{w}{string}{w}")" {return URI;}
+{U}{R}{L}("{w}{url}{w}")" {return URI;}
+
{ident}"(" {return FUNCTION;}
-U\+{range} {return UNICODERANGE;}
-U\+{h}{1,6}-{h}{1,6} {return UNICODERANGE;}
-
. {return *yytext;}