Showing that pixels must become larger if the viewing distance increases
This CSS3 module describes the various values and units that CSS properties accept. Also, it describes how values are computed from "specified" through "computed" and "used" into "actual" values. The main purpose of this module is to define common values and units in one specification which can be referred to by other modules. As such, it does not make sense to claim conformance with this module alone.
All features described in this specification that also exist in CSS 2.1 [[!CSS21]] are intended to be backwards compatible. In case of conflict between this draft and CSS 2.1 [[!CSS21]], CSS 2.1 probably represents the intention of the CSS WG better than this draft (other than on values and units that are new to CSS3).
This is a draft of a module of CSS level 3. It will probably be bundled with some other modules before it becomes a W3C Recommendation.
The value definition field of each CSS property can contain keywords,
data types (which appear between ''<'' and ''>''), and information on how
they can be combined.
Generic data types (<length> being the most widely used)
that can be used by many properties are described in this specification,
while more specific data types (e.g., <border-width>)
are described in the corresponding modules.
This module replaces and extends the data type definitions in [[!CSS21]] sections 1.4.2.1, 4.3, and A.2.
The syntax described here is used to define the set of valid values for CSS properties. A property value can have one or more components.
Component value types are designated in several ways:
auto)
<length>, <percentage>, etc.).
<'border-width'> <'background-attachment'>, etc.).
In this case, the type name is the property name (complete with quotes)
between the brackets. Such a type does not
include the value 'inherit'.
<spacing>. Notice the distinction between
<border-width> and <'border-width'>:
the latter is defined as the value of the 'border-width' property,
the former requires an explicit expansion elsewhere.
The definition of a non-terminal is located near its first appearance
in the specification.
Some property value definitions also include the slash (/) and/or the comma (,) as literals. These represent their corresponding tokens.
All CSS properties also accept the keyword values ''inherit'' and ''initial'' as their property value, but for readability these are not listed explicitly in the property value syntax definitions. These keywords cannot be combined with other component values in same declaration; such a declaration is invalid. For example, ''background: url(corner.png) no-repeat, inherit;'' is invalid.
Component values can be arranged into property values as follows:
Juxtaposition is stronger than the double ampersand, the double ampersand is stronger than the double bar, and the double bar is stronger than the bar. Thus, the following lines are equivalent:
a b | c || d && e f [ a b ] | [ c || [ d && [ e f ]]]
Every type, keyword, or bracketed group may be followed by one of the following modifiers:
Component values are specified in terms of tokens, as described in Chapter 4
of [[!CSS21]].
As the grammar allows spaces between tokens in the components of the
value production, spaces may appear between tokens in
property values.
Note: In many cases, spaces will in fact be
required between tokens in order to distinguish them from
each other. For example, the value ''1em2em'' would be parsed as a
single DIMEN token with the number ''1'' and the identifier
''em2em'', which is an invalid unit. In this case, a space would be
required before the ''2'' to get this parsed as the two lengths ''1em''
and ''2em''.
Below are some examples of properties with their corresponding value definition fields
| Property | Value definition field | Example value |
|---|---|---|
| 'orphans' | <integer> | ''3'' |
| 'text-align' | left | right | center | justify | ''center'' |
| 'padding-top' | <length> | <percentage> | ''5%'' |
| 'outline-color' | <color> | invert | ''#fefefe'' |
| 'text-decoration' | none | underline || overline || line-through || blink | ''overline underline'' |
| 'font-family' | <family-name># | ''"Gill Sans", Futura, sans-serif'' |
| 'border-width' | [ <length> | thick | medium | thin ]{1,4} | ''2px medium 4px'' |
| 'text-shadow' | [ inset? && [ <length>{2,4} && <color>? ] ]# | none | ''3px 3px rgba(50%, 50%, 50%, 50%), lemonchiffon 0 0 4px inset'' |
| 'voice-pitch' | <frequency> && absolute | [[x-low | low | medium | high | x-high] || [<frequency> | <semitones> | <percentage>]] | ''-2st x-low'' |
The generic data types described in the next sections use some common syntactic building blocks and terms that are described in this section.
A string is a sequence of characters enclosed by double quotes or single quotes. Double quotes cannot occur inside double quotes, unless escaped (as '\"' or as '\22'). Analogously for single quotes ("\'" or "\27").
content: "this is a 'string'."; content: "this is a \"string\"."; content: 'this is a "string".'; content: 'this is a \'string\'.';
A string cannot directly contain a newline. To include a newline in a string, use the escape "\A" (hexadecimal A is the line feed character in Unicode (U+000A), but represents the generic notion of "newline" in CSS). See the 'content' property for an example.
It is possible to break strings over several lines, for aesthetic or other reasons, but in such a case the newline itself has to be escaped with a backslash (\). The newline is subsequently removed from the string. For instance, the following two selectors are exactly the same:
a[title="a not s\
o very long title"] {/*...*/}
a[title="a not so very long title"] {/*...*/}
Some values use a functional notation to type values and to and lump values together. The syntax starts with the name of the function followed by a left parenthesis followed by optional whitespace followed by the argument(s) to the functions followed by optional whitespace followed by a right parenthesis. If a function takes more than one argument, the arguments are separated by a comma (',') with optional whitespace before and after the comma.
Some properties accept space- or comma-separated lists of values. A value that is composed of several values with spaces or commas between them, is called a compound value. A value that is not a compound value is a simple value.
An identifier is a sequence of characters conforming to
the IDENT token in the
grammar. [[!CSS21]]
Identifiers cannot be quoted; otherwise they would be interpreted
as a string.
In the value definition fields, keywords with a pre-defined meaning appear literally. Keywords are CSS identifiers and are interpreted case-insensitively within the ASCII range (i.e., [a-z] and [A-Z] are equivalent).
For example, here is the value definition for the 'border-collapse' property:
Value: collapse | separate
And here is an example of its use:
table { border-collapse: separate }
As defined above, all properties accept the ''initial'' and ''inherit'' keywords, which represent value concepts common to all CSS properties.
The ''inherit'' keyword is defined in [[!CSS21]].
The ''initial'' keyword represents the value that is designated as the property's initial value. [[CSS3CASCADE]]
Should these keywords affect the specified or computed value? See various issues.
Would it be useful to have a 'default' value, defined to be equivalent to 'inherit' for properties that are inherited by default and equivalent to 'initial' for properties that are not inherited by default? This might be easier for authors to use than 'initial' and 'inherit' since it wouldn't require thinking about whether a property is inherited by default or not (which isn't obvious for some properties, such as text-decoration and visibility).
Some properties accept arbitrary user-defined identifiers as a
component value. This generic data type is denoted by
<identifier>,
and represents any valid CSS identifier that does not
otherwise appear as a pre-defined keyword in that property's value
definition.
Such identifiers are fully case-sensitive, even in the ASCII range
(e.g. ''example'' and ''EXAMPLE'' are two different, unrelated
user-defined identifiers).
Integer values are denoted by
<integer>.
An integer is one or more decimal digits ''0'' through ''9''
and corresponds to a subset of the NUMBER token in the
grammar.
Integers may be immediately preceded by ''-'' or ''+'' to indicate the
sign.
Properties may restrict the integer value to some range. If the value is outside the allowed range, the declaration is invalid and must be ignored.
Number values are denoted by
<number>.
A number is either an integer, or zero or more decimal
digits followed by a dot (.) followed by one or more decimal digits.
It corresponds to the NUMBER token in the
grammar.
Like integers, numbers may also be immediately preceded by ''-'' or ''+''
to indicate the sign.
Properties may restrict the number value to some range. If the value is outside the allowed range, the declaration is invalid and must be ignored.
A percentage value is denoted by
<percentage>,
consists of a <number> immediately followed by a percent
sign ''%''. It corresponds to the PERCENTAGE token in the
grammar.
Percentage values are always relative to another value, for example a length. Each property that allows percentages also defines the value to which the percentage refers. The value may be that of another property for the same element, a property for an ancestor element, or a value of the formatting context (e.g., the width of a containing block). When a percentage value is set for a property of the root element and the percentage is defined as referring to the inherited value of some property, the resultant value is the percentage times the initial value of that property.
Properties may restrict the percentage value to some range. If the value is outside the allowed range, the declaration is invalid and must be ignored.
Lengths refer to distance measurements and are denoted by
<length> in the
property definitions.
A length is a dimension. A zero length may be represented
instead as the <number> ''0''. (In other words,
for zero lengths the unit identifier is optional.)
DIMENSION token in the
grammar.
[[!CSS21]] Like keywords, unit identifiers are case-insensitive within
the ASCII range.
Properties may restrict the length value to some range. If the value is outside the allowed range, the declaration is invalid and must be ignored.
While some properties allow negative length values, this may complicate the formatting and there may be implementation-specific limits. If a negative length value is allowed but cannot be supported, it must be converted to the nearest value that can be supported.
In cases where the used length cannot be supported, user agents must approximate it in the actual value.
There are two types of length units: relative and absolute.
Relative length units specify a length relative to another length. Style sheets that use relative units can more easily scale from one output environment to another.
The relative units are:
| unit | relative to |
|---|---|
| ''em'' | font size of the element |
| ''ex'' | x-height of the element's font |
| ''ch'' | width of the "0" glyph in the element's font |
| ''rem'' | font size of the root element |
| ''vw'' | viewport's width |
| ''vh'' | viewport's height |
| ''vm'' | minimum of the viewport's height and width |
Child elements do not inherit the relative values as specified for their parent; they inherit the computed values.
Aside from ''rem'' (which refers to the font-size of the root element), the font-relative lengths refer to the computed font metrics of the element on which they are used. The exception is when they occur in the value of the 'font-size' property itself, in which case they refer to the font metrics of the parent element (or the font metrics corresponding to the initial values of the 'font' property, if the element has no parent).
Equal to the computed value of the 'font-size' property of the element on which it is used.
The rule:
h1 { line-height: 1.2em }
means that the line height of h1 elements will be
20% greater than the font size of h1 element. On the
other hand:
h1 { font-size: 1.2em }
means that the font size of h1 elements will be 20%
greater than the font size inherited by h1 elements.
Equal to the font's x-height. The x-height is so called because it is often equal to the height of the lowercase "x". However, an ''ex'' is defined even for fonts that do not contain an "x".
The x-height of a font can be found in different ways. Some fonts contain reliable metrics for the x-height. If reliable font metrics are not available, UAs may determine the x-height from the height of a lowercase glyph. One possible heuristic is to look at how far the glyph for the lowercase "o" extends below the baseline, and subtract that value from the top of its bounding box. In the cases where it is impossible or impractical to determine the x-height, a value of 0.5em must be assumed.
Equal to the advance measure of the "0" (ZERO, U+0030) glyph found in the font used to render it.
Equal to the computed value of 'font-size' on the root element.
When specified on the 'font-size' property of the root element, the ''rem'' units refer to the property's initial value.
The viewport-relative lengths are relative to the size of the initial containing block. When the height or width of the viewport is changed, they are scaled proportionally.
In the example below, if the width of the viewport is 200mm,
the font size of h1 elements will be
16mm (i.e. (8×200mm)/100).
h1 { font-size: 8vw }
Do we need this now that we have the min() function?
The absolute length units are fixed in relation to each other and anchored to some physical measurement. They are mainly useful when the output environment is known. The absolute units consist of the physical units (in, cm, mm, pt, pc) and the px unit:
| unit | definition |
|---|---|
| ''cm'' | centimeters |
| ''mm'' | millimeters |
| ''in'' | inches; 1in is equal to 2.54cm |
| ''px'' | pixels; 1px is equal to 1/96th of 1in |
| ''pt'' | points; 1pt is equal to 1/72nd of 1in |
| ''pc'' | picas; 1pc is equal to 12pt |
h1 { margin: 0.5in } /* inches */
h2 { line-height: 3cm } /* centimeters */
h3 { word-spacing: 4mm } /* millimeters */
h4 { font-size: 12pt } /* points */
h4 { font-size: 1pc } /* picas */
p { font-size: 12px } /* px */
For a CSS device, these dimensions are either anchored (i) by relating the physical units to their physical measurements, or (ii) by relating the pixel unit to the reference pixel. For print media and similar high-resolution devices, the anchor unit should be one of the standard physical units (inches, centimeters, etc). For lower-resolution devices, and devices with unusual viewing distances, it is recommended instead that the anchor unit be the pixel unit. For such devices it is recommended that the pixel unit refer to the whole number of device pixels that best approximates the reference pixel.
Note that if the anchor unit is the pixel unit, the physical units might not match their physical measurements. Alternatively if the anchor unit is a physical unit, the pixel unit might not map to a whole number of device pixels.
Note that this definition of the pixel unit and the physical units differs from previous versions of CSS. In particular, in previous versions of CSS the pixel unit and the physical units were not related by a fixed ratio: the physical units were always tied to their physical measurements while the pixel unit would vary to most closely match the reference pixel. (This change was made because too much existing content relies on the assumption of 96dpi, and breaking that assumption breaks the content.)
The reference pixel is the visual angle of one pixel on a device with a pixel density of 96dpi and a distance from the reader of an arm's length. For a nominal arm's length of 28 inches, the visual angle is therefore about 0.0213 degrees. For reading at arm's length, 1px thus corresponds to about 0.26 mm (1/96 inch).
The image below illustrates the effect of viewing distance on the size of a reference pixel: a reading distance of 71 cm (28 inches) results in a reference pixel of 0.26 mm, while a reading distance of 3.5 m (12 feet) results in a reference pixel of 1.3 mm.
Showing that pixels must become larger if the viewing distance increases
This second image illustrates the effect of a device's resolution on the pixel unit: an area of 1px by 1px is covered by a single dot in a low-resolution device (e.g. a typical computer display), while the same area is covered by 16 dots in a higher resolution device (such as a printer).
Showing that more device pixels (dots) are needed to cover a 1px by 1px area on a high-resolution device than on a low-res one
Angle values are dimensions denoted by <angle>. The angle unit identifiers are:
For example, a right angle is '90deg' or '100grad' or '0.25turn' or approximately '1.570796326794897rad'.
Time values are dimensions denoted by <time>. The time unit identifiers are:
Properties may restrict the time value to some range. If the value is outside the allowed range, the declaration is invalid and must be ignored.
Frequency values are dimensions denoted by <frequency>. The frequency unit identifiers are:
For example, when representing sound pitches, 200Hz (or 200hz) is a bass sound, and 6kHz (or 6khz) is a treble sound.
The calc(), min(), and max() functions can be used wherever length, frequency, angle, time, or number values are allowed.
section {
float: left;
margin: 1em; border: solid 1px;
width: calc(100%/3 - 2*1em - 2*1px);
}
p {
margin: calc(1rem - 2px) calc(1rem - 1px);
}
p { font-size: min(10px, 3em) }
blockquote { font-size: max(30px, 3em) }
.box { width: min(10% + 20px, 300px) }
The expression language of these functions is described by the grammar and prose below.
S : calc | min | max;
calc : "calc(" S* sum ")" S*;
min : "min(" S* sum [ "," S* sum ]* ")" S*;
max : "max(" S* sum [ "," S* sum ]* ")" S*;
sum : product [ [ "+" | "-" ] S* product ]*;
product : unit [ [ "*" | "/" | "mod" ] S* unit ]*;
unit : ["+"|"-"]? [ NUMBER S* | DIMENSION S* | PERCENTAGE S* |
min | max | "(" S* sum ")" S* ];
The context of the expression imposes a target type, which is one of length, frequency, angle, time, or number. NUMBER tokens are of type number. DIMENSION tokens have types of their units ('cm' is length, 'deg' is angle etc.); any DIMENSION whose type does not match the target type is not allowed and must be a parse error. If percentages are accepted in that context and convertible to the target type, a PERCENTAGE token in the expression has the target type; otherwise percentages are not allowed and must be a parse error.
To make expressions simpler, operators have restrictions on the types they accept. At each operator, the types of the left and right side have to be checked for these restrictions. If compatible, they return roughly as follows (the following ignores precedence rules on the operators for simplicity):
Division by zero is a parse error.
The value resulting from an expression must be clamped to the range allowed in the target context.
width: calc(5px - 10px); width: 0px;
Given the complexities of 'width' and 'height' on table cells and table elements, calc() expressions for 'width' and 'height' on table columns, table column groups, table rows, table row groups, and table cells in both auto and fixed layout tables are treated as if 'auto' had been specified.
Strings are denoted by <string> in the value definitions.
This section is not normative. The CSS3 Color module [[!CSS3COLOR]] defines the CSS3 color values.
Color values are denoted by <color> in the value definitions.
A color value can either be a keyword, a numerical specification in a functional notation, or a numerical RGB specification in a hexadecimal notation. The hexadecimal notation is special shorthand format that allows compact color descriptions.
em { color: #F00 }
span.issue { color: red }
* { color: hsl(120, 75%, 75%) }
Describe the feature fully here, not just a delta from CSS 21.
When attr is set on a pseudo-element, it should apply to the originating element
In CSS2.1 [[!CSS21]], the 'attr()' expression always returns a string. In CSS3, the 'attr()' expression can return many different types. The new syntax for the attr() expression is:
'attr(' ident [ ',' <type> [ ',' <value> ]? ]? ')'
The first argument represents the attribute name. The value of the attribute with that name on the element whose computed values are being computed is used as the value of the expression, according to the rules given below.
The first argument accepts an optional namespace prefix to identify the namespace of the attribute. The namespace prefix and the attribute name is separated by '|', with no whitespace before or after the separator [[CSS3NAMESPACE]].
The second argument (which is optional but must be present if the third argument is present) is a <type> and tells the UA how to interpret the attribute value. It may be one of the values from the list below.
The third argument (which is optional) is a CSS value which must be valid where the attr() expression is placed. If it is not valid, then the whole attr() expression is invalid.
If the attribute named by the first argument is missing, cannot be parsed, or is invalid for the property, then the value returned by attr() will be the third argument, or, if the third argument is absent, will be the value given as the default for the relevant type in the list below.
Should there also be a "keyword" type to, e.g., support 'float: attr(align)'
If the <type> is missing, 'string' is implied.
Ideally, it shouldn't be necessary to specify the
type if it is obvious. For example, this should be valid:
"background-image: attr(href);". This could be described as:
If the property only accepts one type of value (aside from
'inherit' and 'initial'), that type is implied
.
The attr() form is only valid if the type given (or implied, if it is missing) is valid for the property. For example, all of the following are invalid and would cause a parse-time error (and thus cause the relevant declaration, in this case all of them, to be ignored):
content: attr(title, color); /* 'content' doesn't accept colors */
content: attr(end-of-quote, string, inherit) close-quote; /* the
'inherit' value is not allowed there, since the result would be
'inherit close-quote', which is invalid. */
margin: attr(vertical, length) attr(horizontal, deg); /* deg
units are not valid at that point */
color: attr(color); /* 'color' doesn't accept strings */
The attr() expression cannot return everything, for example it cannot do counters, named strings, quotes, or values such as 'auto', 'nowrap', or 'baseline'. This is intentional, as the intent of the 'attr()' expression is not to make it possible to describe a presentational language's formatting using CSS, but to enable CSS to take semantic data into account.
Note that the default value need not be of the type given. For instance, if the type required of the attribute by the author is 'px', the default could still be '5em'.
Examples:
<stock>
<wood length="12"/>
<wood length="5"/>
<metal length="19"/>
<wood length="4"/>
</stock>
stock::before {
display: block;
content: "To scale, the lengths of materials in stock are:";
}
stock > * {
display: block;
width: attr(length, em); /* default 0 */
height: 1em;
border: solid thin;
margin: 0.5em;
}
wood {
background: orange url(wood.png);
}
metal {
background: silver url(metal.png);
}
/* this also uses a possible extension to the 'content' property
to handle replaced content and alternatives to unavailable,
corrupted or unsupported content */
img {
content: replaced attr(src, url), attr(alt, string, none);
height: attr(height, px, auto);
width: attr(width, px, auto);
}
The attr() expression cannot currently fall back onto another attribute. Future versions of CSS may extend attr() in this direction.
Should 'attr()' be allowed on any property, in any source language? For example, do we expect UAs to honor this rule for HTML documents?: P[COLOR] { color: attr(COLOR, color) }.
URLs (Uniform Resource Locators, see [[RFC1738]] and [[RFC1808]]) provide the address of a resource on the Web. An alternative and more general term is URIs (Uniform Resource Identifiers, see [!URI]). This specification uses the term URI.
For historical reasons, the name of the URI function is "url". The URI function takes one URI as the argument. The URI may be quoted with single quote (') or double quote (") characters. If quoted, the two quote characters must be the same.
body { background: url("http://www.example.com/pinkish.gif") }
An example without quotes:
li { list-style: url(http://www.example.com/redball.png) disc }
Parentheses, commas, whitespace characters, single quotes (') and double quotes (") appearing in a URI must be escaped with a backslash: '\(', '\)', '\,'.
Depending on the type of URI, it might also be possible to write the above characters as URI-escapes (where "(" = %28, ")" = %29, etc.) as described in [!URI].
In order to create modular style sheets that are not dependent on the absolute location of a resource, authors should use relative URIs. Relative URIs (as defined in [[RFC1808]]) are resolved to full URIs using a base URI. RFC 1808, section 3, defines the normative algorithm for this process. For CSS style sheets, the base URI is that of the style sheet, not that of the source document.
For example, suppose the following rule:
body { background: url("yellow") }
is located in a style sheet designated by the URI:
http://www.example.org/style/basic.css
The background of the source document's BODY will be tiled with whatever image is described by the resource designated by the URI
http://www.example.org/style/yellow
User agents may vary in how they handle URIs that designate unavailable or inapplicable resources.
TBD.
Some properties accept a series of length values that, in sum, should add up to a certain length. To take up any remaining space, fractions can be used.
The fr unit is used to distribute any remaining space in a series of length values. If multiple fractions are specified, they take up space proportionally to their numeric value.
border-parts: 10px 1fr 10px; border-parts: 10px 1fr 10px 1fr 10px; border-parts: 10px 2fr 10px 2fr 10px;
The ''fr'' unit can only be used in combination with regular length units.
A grid is a set of invisible vertical and horizontal lines that can be used to align content. In CSS3, a grid lines can be established implicitly or explicitly [[!CSS3COL]] [[!CSS3GRID]]. In any case, the distance between grid lines can be referred to by the ''gr'' unit.
The gr unit is used to position elements in relation to grid lines.
img {
float: top left multicol;
float-offset: 2gr;
width: 1gr }
}
Grid lines can be laid out in uneven patterns. Therefore, the ''gr'' unit is not linear.
For example, "2gr" is not necessarily twice as long as "1gr".
The final value of a CSS3 property for a given element is the result of a four-step calculation. First, cascading and inheritance yields the specified value [[!CSS3CASCADE]]. Second, relative values are computed into absolute values as far as possible without formatting the document, thereby yielding the computed value. The computed value is transformed into the used value in the formatting process. Finally, the computed value is transformed to the actual value based on constraints in the user agent.
The specified value is the output of the cascading and inheritance process [[!CSS3CASCADE]].
Specified values may be absolute (i.e., they are not specified relative to another value, as in 'red' or '2mm') or relative (i.e., they are specified relative to another value, as in 'auto', '2em'). For absolute values, no processing is needed to find the computed value.
For relative values, on the other hand, computation is necessary to find the computed values: percentages must be multiplied by a reference value (each property defines which value that is), values with relative units (em, ex, px) must be made absolute by multiplying with the appropriate font or pixel size, 'auto' values must be computed by the formulas given with each property, certain keywords (e.g., 'smaller', 'bolder') must be replaced according to their definitions. See example (f), (g) and (h) in the table below.
Also, relative URIs are computed into absolute URIs at this stage. The computed value of invalid and absolute URIs is the same as the specified value.
Computed values are processed as far as possible without formatting the document. Some values, however, can only be determined when the document is being laid out. For example, if the width of an element is set to be a certain percentage of its containing block, the width cannot be determined until the width of the containing block has been determined. The used value is the result of taking the computed value and resolving any remaining dependencies into an absolute value.
A used value is in principle ready to be used, but a user agent may not be able to make use of the value in a given environment. For example, a user agent may only be able to render borders with integer pixel widths and may therefore have to approximate the computed width. Also, the font size of an element may need adjustment based on the availability of fonts or the value of the 'font-size-adjust' property. The actual value is the computed value after adjustments have been made.
By probing the actual values of elements, much can be learned about how the document is laid out. However, not all information is recorded in the actual values. For example, the actual value of the 'page-break-after' property does not reflect whether there is a page break or not after the element. Similarly, the actual value of 'orphans' does not reflect how many orphan lines there is in a certain element. See examples (j) and (k) in the table below.
| Example | Winning declaration | Property | Specified value | Computed value | Used value | Actual value |
|---|---|---|---|---|---|---|
| a | text-align: left | text-align | left | left | left | left |
| b | border-width: inherit | border-top-width, border-right-width, border-bottom-width, border-left-width | 4.2px | 4.2px | 4.2px | 4px |
| c | (no winning declaration) | width | auto (initial value) | auto | 120px | 120px |
| d | list-style-position: inherit | list-style-position | inside | inside | inside | inside |
| e | list-style-position: initial | list-style-position | outside (initial value) | outside | outside | outside |
| f | font-size: 1.2em | font-size | 1.2em | 14.1px | 14.1px | 14px |
| g | width: 80% | width | 80% | 80% | 354.2px | 354px |
| h | width: auto | width | auto | auto | 134px | 134px |
| i | height: auto | height | auto | auto | 176px | 176px |
| j | (no winning declaration) | page-break-after | auto (initial value) | auto | auto | auto |
| k | orphans: 3 | orphans | 3 | 3 | 3 | 3 |
Comments and suggestions from Giovanni Campagna, Christoph Päper, Keith Rarick, Alex Mogilevsky, Ian Hickson, David Baron, Edward Welbourne, Boris Zbarsky, Björn Höhrmann and Michael Day improved this module.