[css2] Minor fixes for clarity, presentation. Added statement about no negative frequencies, dropped STYLE from counters section (replaced with consistent list-style-type), moved around color info for clarity, @-rule to at-rule

ianbjacobs · ianbjacobs · commit 1188b53b0e97 · 1998-04-09T14:45:33.000Z
--HG--
extra : convert_revision : svn%3A73dc7c4b-06e6-40f3-b4f7-9ed1dbc14bfc/trunk%401484
diff --git a/css2/syndata.src b/css2/syndata.src
@@ -1,6 +1,6 @@
 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
 <html lang="en">
-<!-- $Id: syndata.src,v 2.50 1998-04-07 20:47:27 ijacobs Exp $ -->
+<!-- $Id: syndata.src,v 2.51 1998-04-09 14:45:33 ijacobs Exp $ -->
 <HEAD>
 <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
 <TITLE>CSS2 syntax and basic data types</TITLE>
@@ -125,7 +125,7 @@ href="#escaped-characters">escaped characters.</a>
 <H3><a name="keywords">Keywords</a></H3>
 
 <!-- provide better explanation of where keywords appear:
-media types, @rules, etc. -IJ -->
+media types, at-rules, etc. -IJ -->
 
 <P>Keywords have the form of identifiers. Keywords must not be placed
 between quotes ("..." or '...'). Thus,
@@ -159,15 +159,15 @@ background: "red";
     <LI> All CSS style sheets are <span class="index-inst" title="case
     sensitivity">case-insensitive</span>, except for parts that are
     not under the control of CSS. For example, the case-sensitivity of
-    values of the HTML attributes 'id' and 'class', of font names, and
+    values of the HTML attributes "id" and "class", of font names, and
     of URIs lies outside the scope of this specification. Note in
     particular that element names are case-insensitive in HTML, but
     case-sensitive in XML.
 
     <LI> In CSS2, <span class="index-def"
     title="identifier|identifier, definition of"><a
     name="value-def-identifier"><dfn>identifiers</dfn></a></span>
-    (including element names, classes and IDs in <a
+    (including element names, classes, and IDs in <a
     href="selector.html">selectors</a>) can contain only the
     characters [A-Za-z0-9] and ISO 10646 characters 161 and higher,
     plus the hyphen (-); they cannot start with a hyphen or a
@@ -180,7 +180,7 @@ background: "red";
 
     <LI> In CSS2, a backslash (\) character indicates three types of
     <span class="index-def" title="backslash escapes">
-    <a name="escaped-characters">character escape</a></span>.
+    <a name="escaped-characters">character escapes</a></span>.
 
     <P>First, inside a <a href="#strings">string</a>, a backslash
     followed by a newline is ignored (i.e., the string is deemed not
@@ -223,7 +223,7 @@ background: "red";
 <P> A CSS style sheet, for any version of CSS, consists of a list of
 <span class="index-inst" title="statements"><em>statements</em></span>
 (see the grammar above).  There are two kinds of statements: <span
-class="index-inst" title="at-rules|@-rules"><em>at-rules</em></span>
+class="index-inst" title="at-rules"><em>at-rules</em></span>
 and <span class="index-inst" title="rule sets"><em>rule
 sets.</em></span> There may be <a href="#whitespace">whitespace</a>
 around the statements.
@@ -233,17 +233,19 @@ around the statements.
 
 <!-- Should comments be defined as white space? -->
 
-<H3><a name="at-rules">At-rules</a></H3>
+<H3><span class="index-def" title="at-rule">
+<a name="at-rules">At-rules</a></span></H3>
 
 <P> At-rules start with an <DFN>at-keyword</DFN>, an '@' character
-followed by an <a href="#value-def-identifier">identifier</a> (for
-example, '@import', '@page').
+followed immediately by an <a
+href="#value-def-identifier">identifier</a> (for example, '@import',
+'@page').
 
 <P> An at-rule consists of everything up to and including the next
 semicolon (;) or the next <a href="#block">block,</a> whichever comes
 first. A CSS user agent that encounters an unrecognized at-rule must
 <span class="index-inst" title="ignore"><a href="#ignore">ignore</a></span>
-the whole of the @-rule and continue parsing after it.
+the whole of the at-rule and continue parsing after it.
 
 <P>CSS2 user agents must <span class="index-inst" title="ignore"><a
 href="#ignore">ignore</a></span> any <a
@@ -478,7 +480,8 @@ beginning and end), but otherwise acts as if it had not been there.
 
 <P>To ensure that new properties and new values for existing
 properties can be added in the future, user agents are required to
-obey the following rules when they encounter these parsing errors:</p>
+obey the following rules when they encounter the following
+scenarios:</p>
 
 <UL>
 <LI><strong>Unknown properties.</strong> User agents must <span
@@ -627,7 +630,7 @@ quad-width in typographic texts.)
 name="ex">'ex'</a></span> unit is defined by the font's <span
 class="descinst-x-height">'x-height'</span>. The x-height is so called
 because it is often equal to the height of the lowercase "x". However,
-an 'ex' is be defined even for fonts that don't contain an "x".
+an 'ex' is defined even for fonts that don't contain an "x".
 
 <div class="example">
 <P>The rule:
@@ -664,7 +667,7 @@ degrees.
 
 <p>For reading at arm's length, 1px thus corresponds to about 0.28&nbsp;mm
 (1/90&nbsp;inch). When printed on a laser printer, meant for reading at a
-little less than arm's length (55&nbsp;cm, 21&nbsp;inch), 1px is about
+little less than arm's length (55&nbsp;cm, 21&nbsp;inches), 1px is about
 0.21&nbsp;mm. On a 300 dots-per-inch (dpi) printer, that may be
 rounded up to 3 dots (0.25&nbsp;mm); on a 600&nbsp;dpi printer, it can
 be rounded to 5 dots.
@@ -730,8 +733,7 @@ H4 { font-size: 1pc }     /* picas */
 </div>
 
 <P> In cases where the specified length cannot be supported, user
-agents must approximate it. For all CSS2 properties, further
-computations and inheritance is be based on the approximated value.
+agents must approximate it in the actual value.
 
 <H3> <A NAME="percentage-units">Percentages</A></H3>
 
@@ -740,7 +742,10 @@ class="index-def" title="&lt;percentage&gt;::definition of"><a
 name="value-def-percentage"
 class="value-def">&lt;percentage&gt;</a></span> in this specification)
 is an optional sign character ('+' or '-', with '+' being the default)
-immediately followed by a number immediately followed by '%'.
+immediately followed by a <span class="index-inst"
+title="&lt;number&gt;"><span
+class="value-inst-number">&lt;number&gt;</span></span> immediately
+followed by '%'.
 
 <P> Percentage values are always relative to another value, for
 example a length. Each property that allows percentages also defines
@@ -764,7 +769,7 @@ value (120%):
 
 <PRE>
 P { font-size: 10pt }
-P { line-height: 120% }  /* relative to 'font-size', i.e., 12pt */
+P { line-height: 120% }  /* 120% of 'font-size' */
 </PRE>
 </div>
 
@@ -778,8 +783,7 @@ class="index-def" title="URN (Uniform Resource Name)|Uniform Resource
 Name (URN)">URN</span> (Uniform Resource Name). Together they are
 called <span class="index-def" title="Resource Identifier (URI)|URI
 (Uniform Resource Identifier)">URIs</span> (Uniform Resource
-Identifiers, see [[URI]]). This specification uses the term URI
-throughout.
+Identifiers, see [[URI]]). This specification uses the term URI.
 
 <P>URI values in this specification are denoted by <span
 class="index-def" title="&lt;uri&gt;::definition of"><a
@@ -817,15 +821,21 @@ algorithm for this process. For CSS style sheets, the base URI is that
 of the style sheet, not that of the source document.
 
 <div class="example">
-<P>For example, suppose the following rule is located in a style sheet
-designated by the URI <tt>http://www.myorg.org/style/basic.css</tt>:
+<P>For example, suppose the following rule:</p>
+
 <PRE>
 BODY { background: url(yellow) }
 </PRE>
 
+<P>is located in a style sheet designated by the URI:</p>
+
+<PRE>http://www.myorg.org/style/basic.css</PRE>
+
 <P>The background of the source document's BODY will be tiled with
 whatever image is described by the resource designated
-by the URI <tt>http://www.myorg.org/style/yellow</tt>.
+by the URI
+
+<PRE>http://www.myorg.org/style/yellow</PRE>
 </div>
 
 <P>User agents may vary in how they handle URIs that designate
@@ -843,7 +853,7 @@ properties). To refer to the value of a counter, the notation
 'counter(&lt;identifier&gt;)'</span> or 'counter(&lt;identifier&gt;,
 &lt;list-style-type&gt;)' is used.  The default style is 'decimal'.
 
-<p>To refer to a sequence of nested counters of the same name the
+<p>To refer to a sequence of nested counters of the same name, the
 notation is 'counters(&lt;identifier&gt;, &lt;string&gt;)' or
 'counters(&lt;identifier&gt;, &lt;string&gt;,
 &lt;list-style-type&gt;)'. See <a href="generate.html#scope">"Nested
@@ -853,7 +863,7 @@ href="generate.html">generated content</a>.
 <p>In CSS2, the values of counters can
 only be referred to from the <span
 class="propinst-content">'content'</span> property. Note that 'none'
-is a possible <var>style</var>; 'counter(x,
+is a possible &lt;list-style-type&gt;: 'counter(x,
 none)' yields an empty string.
 
 <div class="example">
@@ -881,7 +891,12 @@ is either a keyword or a numerical RGB specification.
 
 <P> The list of keyword color names is: aqua, black, blue, fuchsia,
 gray, green, lime, maroon, navy, olive, purple, red, silver, teal,
-white, and yellow. These 16 colors are defined in HTML 4.0 ([[-HTML40]]).
+white, and yellow. These 16 colors are defined in HTML 4.0
+([[-HTML40]]). In addition to these color keywords, users may specify
+keywords that correspond to the colors used by certain objects in the
+user's environment. Please consult the section on <a
+href="./ui.html#system-colors">system colors</a> for more information.
+
 
 <div class="example"><P>
 <PRE>
@@ -903,28 +918,23 @@ EM { color: rgb(100%, 0%, 0%) } /* float range 0.0% - 100.0% */
 </PRE>
 </div>
 
-<P>In addition to these color keywords, users may specify keywords that
-correspond to the colors used by certain objects in the user's
-environment. Please consult the section on <a
-href="./ui.html#system-colors">system colors</a> for more information.
-
 <P> The format of an RGB value in hexadecimal notation is a '#'
 immediately followed by either three or six hexadecimal
 characters. The three-digit RGB notation (#rgb) is converted into
 six-digit form (#rrggbb) by replicating digits, not by adding
-zeros. For example, #fb0 expands to #ffbb00. This makes sure that
+zeros. For example, #fb0 expands to #ffbb00. This ensures that
 white (#ffffff) can be specified with the short notation (#fff) and
 removes any dependencies on the color depth of the display.
 
 <P> The format of an RGB value in the functional notation is 'rgb('
 followed by a comma-separated list of three numerical values (either
-three integer values, or three percentage values) followed by ')'.
+three integer values or three percentage values) followed by ')'.
 The integer value 255 corresponds to 100%, and to F or FF in the
 hexadecimal notation: rgb(255,255,255) = rgb(100%,100%,100%) =
 #FFF. <a href="#whitespace">Whitespace</a> characters are allowed
 around the numerical values.
 
-<P>Values outside the device gamut should be clipped: the red, green
+<P>Values outside the device gamut should be clipped: the red, green,
 and blue values must be changed to fall within the range supported by
 the device. For a device whose gamut is exactly 0-255 in each of red,
 green, and blue (typical for CRT monitors), the three rules below are
@@ -967,7 +977,7 @@ title="&lt;number&gt;"><span
 class="value-inst-number">&lt;number&gt;</span></span> immediately
 followed by an angle unit identifier.
 
-<P>The following are valid angle unit identifiers:</p>
+<P>Angle unit identifiers are:</p>
 
 <ul>
 <li><strong>deg</strong>: degrees
@@ -993,7 +1003,7 @@ title="&lt;number&gt;"><span
 class="value-inst-number">&lt;number&gt;</span></span> immediately
 followed by a time unit identifier.
 
-<P>The following are valid time unit identifiers:</p>
+<P>Time unit identifiers are:</p>
 
 <UL>
 <LI><strong>ms</strong>: milliseconds
@@ -1015,13 +1025,15 @@ title="&lt;number&gt;"><span
 class="value-inst-number">&lt;number&gt;</span></span> immediately
 followed by a frequency unit identifier.
 
-<p>There are two valid frequency unit identifiers:</p>
+<p>Frequency unit identifiers are:</p>
 
 <ul>
 <li><strong>Hz</strong>: Hertz
 <li><strong>kHz</strong>: kilo Hertz
 </ul>
 
+<p>Frequency values may not be negative.
+
 <P> For example, 200Hz (or 200hz) is a bass sound, and 6kHz (or 6khz)
 is a treble sound.
 
@@ -1073,7 +1085,7 @@ specification ([[-HTML40]], chapter 5), See also the XML 1.0
 specification ([[-XML10]], sections 2.2 and 4.3.3, and Appendix F.
 
 <P>When a style sheet is embedded in another document, such as in the
-STYLE element or STYLE attribute of HTML, the style sheet shares the
+STYLE element or "style" attribute of HTML, the style sheet shares the
 character encoding of the whole document.
 
 <P>When a style sheet resides in a separate file, user agents must
@@ -1127,7 +1139,7 @@ represented in the current character encoding.  These characters must
 be written as <a href="#escaped-characters">escaped</a> references to
 ISO 10646 characters. These escapes serve the same purpose as numeric
 character references in HTML or XML documents (see [[HTML40]],
-Chapters 5 and 25).
+chapters 5 and 25).
 
 <P>The character escape mechanism should be used when only a few
 characters must be represented this way. If most of a document
