w3c
diff --git a/‎css3-values/Overview.src.html‎
Lines changed: 80 additions & 64 deletions b/‎css3-values/Overview.src.html‎
Lines changed: 80 additions & 64 deletions
@@ -65,12 +65,12 @@ <h2 class="no-num no-toc" id="status">Status of this document</h2>
 
 <!--status-->
 
-<p><strong>All features described in this specification that also
+<p>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&nbsp;2.1 [[!CSS21]],
 CSS&nbsp;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).</strong>
+CSS3).
 
 <p>This is a draft of a <a href="http://www.w3.org/TR/css3-roadmap/">module
 of CSS level 3</a>. It will probably be bundled with some other modules
@@ -164,7 +164,7 @@ <h3>Keywords</h3>
 
 <h3>Numbers</h3>
 
-<p>Number values can either be integer or real numbers. Integer values
+<p>Number values can either be integer or real numbers Integer values
 are denoted by <dfn>&lt;integer&gt;</dfn> and real number values are
 denoted by <dfn>&lt;number&gt;</dfn>. Integers and real numbers are
 specified in decimal notation only. An &lt;integer&gt; consists of one
@@ -174,47 +174,70 @@ <h3>Numbers</h3>
 be preceded by a "-" or "+" to indicate the sign, and the sign
 character is considered part of the &lt;number&gt; value.</p>
 
-<p>Note that many properties that allow an integer or real number as a value
+<p>Many properties that allow an integer or real number as a value
 actually restrict the value to some range. If the restriction is to a 
-non-negative value, then a non-negative number type is used.</p>
-
-
-<h3>Non-negative numbers</h3>
+non-negative value, then a non-negative number type is used. 
 
 <p>Non-negative number values can either be integer or real numbers.
 Integer values are denoted by <dfn>&lt;non-negative integer&gt;</dfn>
 and real number values are denoted by <dfn>&lt;non-negative
-number&gt;</dfn>. Integers and real numbers are specified in decimal
-notation only. A &lt;non-negative-integer&gt; consists of one or more
-digits "0" to "9". A &lt;non-negative-number&gt; can either be an
-&lt;integer&gt;, or it can be zero or more digits followed by a dot
-(.) followed by one or more digits. Both non-negative integers and
-non-negative real numbers may be preceded by a "+" to indicate the
-sign, but this is not required and conveys no useful information.</p>
+number&gt;</dfn>. The syntax for non-negative numbers is the same as
+for other numbers execept that the "-" sign is not allowed.
 
-<h3>Numbers with unit identifiers</h3>
 
-<h4>Lengths</h4>
+<h3>Lengths</h3>
 
-<p>Lengths refer to horizontal or vertical measurements.</p>
+<p>Many CSS values consist of a number with a unit identifier. The
+most common types is lengths, but percentages, angles, times, and
+frequences also belong to this group.
 
-<p>The format of a length value (denoted by <dfn>&lt;length&gt;</dfn>)
-is a &lt;number&gt; immediately followed by a unit identifier (e.g.,
-'px', 'pt'). After the '0' length, the unit identifier is
-optional.</p>
+<p>Lengths refer to horizontal or vertical measurements. The format of
+a length value (denoted by <dfn>&lt;length&gt;</dfn>) is a
+&lt;number&gt; immediately followed by a unit identifier (e.g., 'px',
+'pt'). After the '0' length, the unit identifier is optional.</p>
 
-<p>Some properties <em>allow</em> negative length values, but this may
+<p>Some properties allow negative length values, but this may
 complicate the formatting and there may be implementation-specific
 limits. If a negative length value is allowed but cannot be supported,
 it should be converted to the nearest value that can be supported.</p>
 
-<h4>Relative length units</h4>
-
-<p id="absrel-units">There are two types of length units: relative and
-absolute. <dfn>Relative length units</dfn> specify a length relative to
-another length property. Style sheets that use relative units will
+<p>There are several types of length units. Absolute l<dfn>Relative length units</dfn> specify a length relative to
+other lengths. <!--Style sheets that use relative units will
 more easily scale from one medium to another (e.g., from a computer
-display to a laser printer).</p>
+display to a laser printer).--></p>
+
+<h3>Absolute length units</h3>
+
+<p><dfn>Absolute length</dfn> units are useful when the physical
+properties of the output medium are known. The absolute units are:</p>
+
+<table>
+<tr><th>unit<th>definition
+<tr><td><span class="css">in</span><td>inches; 1 inch is equal to 2.54 centimeters.
+<tr><td><span class="css">cm</span><td>centimeters
+<tr><td><span class="css">mm</span><td>millimeters
+<tr><td><span class="css">pt</span><td>points; 1pt is equal to 1/72 inch.
+<tr><td><span class="css">pc</span><td>picas; 1 pica is equal to 12 points.
+</table>
+
+<div class="example">
+<p style="display:none">Examples:</p>
+
+<pre>
+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 */</pre>
+</div>
+
+<p>In cases where the specified length cannot be supported, user agents must
+approximate it in the actual value.</p>
+
+
+<h3>Relative length units</h3>
+
+<p id="absrel-units">
 
 <p>Relative units are:</p>
 
@@ -224,7 +247,7 @@ <h4>Relative length units</h4>
 <tr><td><span class="css">ex</span><td>the <em>x-height</em> of the element's font
 <tr><td><span class="css">px</span<td>viewing device
 <!--
-<tr><td><span class="css">gd</span><td>the grid defined by <span class="property">'layout-grid'</span> described in the CSS3 Text module [[!CSS3TEXT]]
+<tr><td><span class="css">gd</span><td>the grid defined by <span class="property">'layout-grid'</span> described in the CSS3 Text module !CSS3TEXT
 -->
 <tr><td><span class="css">rem</span><td>the font size of the root element
 <tr><td><span class="css">vw</span><td>the viewport's width
@@ -234,6 +257,8 @@ <h4>Relative length units</h4>
 </table>
 
 
+<h4>The 'em' unit</h4>
+
 <p>The <dfn title="em (unit)|quad width">'em'</dfn> unit is equal to
 the computed value of the <span class="property">'font-size'</span>
 property of the element on which it is used. The exception is when
@@ -270,6 +295,7 @@ <h4>Relative length units</h4>
 </pre>
 </div>
 
+<h4>The 'ex' unit</h4>
 
 <p>The <dfn title="x-height|ex (unit)">'ex'</dfn> unit is defined by the
 font's x-height. The x-height is so called because it is often equal to the
@@ -281,6 +307,8 @@ <h4>Relative length units</h4>
 property's <em>initial value</em>.</p>
 
 
+<h4>The 'px' unit</h4>
+
 <p>The pixel unit, <dfn title="pixel unit|px (pixel)::definition
 of">'px'</dfn> is relative to the resolution of the viewing device.
 For example, the viewing device can be a computer display or a
@@ -370,15 +398,18 @@ <h4>Relative length units</h4>
 inheritance, see the "Cascading and Inheritance" module.
 -->
 
+<h4>The 're' unit</h4>
 
-<p>The <dfn title="root em|em (grid)::definition of">'rem'</dfn>
+<p>The <dfn title="root em|em (grid)::definition of">'re'</dfn>
 unit ('root em') is relative to the computed value of the <span
 class="property">'font-size'</span> value of the root element. The
-exception is when 'rem' occurs in the value of the <span
+exception is when 're' occurs in the value of the <span
 class="property">'font-size'</span> property of the root element
 itself, in which case it is relative to the 'medium' font-size. It may
 be used for vertical or horizontal measurement.
 
+<h4>The 'vw' unit</h4>
+
 <p>The <dfn title="vw::definition of">'vw'</dfn> unit is relative to
 the viewport's width. The viewport's width is equal to 100
 'vw' units. 
@@ -396,50 +427,32 @@ <h4>Relative length units</h4>
 window is enlarged), lengths specifed in the 'vh' unit is scaled
 propertionally.
 
+<h4>The 'vh' unit</h4>
+
 <p>The <dfn title="vh::definition of">'vh'</dfn> unit is relative to
 the viewport's height. The viewport's width is equal to 100
 'vh' units. When the height of the viewport is changed (for example,
 when the browser window is enlarged), lengths specifed in the 'vh'
 unit are scaled proportionally.
 
+<h4>The 'vm' unit</h4>
 
 <p>The <dfn title="vm::definition of">'vm'</dfn> unit is relative to
 the viewport's height or width, whichever of the two is smaller.
 The minimum of the viewport's width/height is equivalent to 100 'vm'
 units. When the height or width of the viewport is changed, lengths
 specified in the 'vm' unit are scaled proportionally.
 
+<h3>Fractions</h3>
 
+<h4>The 'fr' unit</h4>
 
-<h4>Absolute length units</h4>
-
-<p id="x41"><dfn>Absolute length</dfn> units are useful when the physical
-properties of the output medium are known. The absolute units are:</p>
-
-<table>
-<tr><th>unit<th>definition
-<tr><td><span class="css">in</span><td>inches; 1 inch is equal to 2.54 centimeters.
-<tr><td><span class="css">cm</span><td>centimeters
-<tr><td><span class="css">mm</span><td>millimeters
-<tr><td><span class="css">pt</span><td>points; 1pt is equal to 1/72 inch.
-<tr><td><span class="css">pc</span><td>picas; 1 pica is equal to 12 points.
-</table>
-
-<div class="example">
-<p style="display:none">Examples:</p>
+<h3>Grids</h3>
 
-<pre>
-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 */</pre>
-</div>
+<h4>The 'gr' unit</h4>
 
-<p>In cases where the specified length cannot be supported, user agents must
-approximate it in the actual value.</p>
 
-<h4>Percentages</h4>
+<h3>Percentages</h3>
 
 <p>The format of a percentage value (denoted by <dfn
 title="&lt;percentage&gt;::definition of">&lt;percentage&gt;</dfn> in this
@@ -472,7 +485,7 @@ <h4>Percentages</h4>
 
 <p class="issue">Do we need a "non-negative percentage", e.g. for "font-size"?
 
-<h4>Angles</h4>
+<h3>Angles</h3>
 
 <p>Angle values (denoted by <dfn
 title="&lt;angle&gt;::definition of">&lt;angle&gt;</dfn> in the text) are
@@ -496,9 +509,8 @@ <h4>Angles</h4>
 '1.570796326794897rad'.</p>
 
 
-<h3>Non-negative numbers with unit identifiers</h3>
 
-<h4>Times</h4>
+<h3>Times</h3>
 
 <p>Time values (denoted by <dfn
 title="&lt;time&gt;::definition of">&lt;time&gt;</dfn> in the text) are used
@@ -513,8 +525,10 @@ <h4>Times</h4>
   <li><dfn title="s (seconds)">s:</dfn> seconds</li>
 </ul>
 
+<p>Time values are always positive.
 
-<h4>Frequencies</h4>
+
+<h3>Frequencies</h3>
 
 <p>Frequency values (denoted by <dfn
 title="&lt;frequency&gt;::definition of">&lt;frequency&gt;</dfn> in the text)
@@ -529,10 +543,12 @@ <h4>Frequencies</h4>
   <li><dfn title="kHz (kilohertz)">kHz:</dfn> kilohertz</li>
 </ul>
 
-
 <p>For example, 200Hz (or 200hz) is a bass sound, and 6kHz (or 6khz) is a
 treble sound.</p>
 
+<p>Frequency values are always positive.
+
+
 <h3>Strings</h3>
 
 <p><dfn title="&lt;string&gt;, definition of">Strings</dfn> can either be
@@ -1203,7 +1219,7 @@ <h3><dfn>Actual values</dfn></h3>
 
 <h2 class="no-num" id="acknowledgments">Acknowledgments</h2>
 
-<p>Comments and suggestions from Ian Hickson, David Baron, Edward Welbourne, Boris Zbarsky, Björn Höhrmann and Michael Day improved this module.
+<p>Comments and suggestions from Alex Mogilevsky, Ian Hickson, David Baron, Edward Welbourne, Boris Zbarsky, Bj&ouml;rn Höhrmann and Michael Day improved this module.
 
 <!--