Copy over Conformance section from CSS3 Backgrounds and Borders

Author: fantasai

css3-text/Overview.src.html

@@ -445,15 +445,60 @@ <h2 id="intro"><span class="secno">1.</span>
 <h2 id="conformance"><span class="secno">2.</span>
   Conformance</h2>
 
-  <p>The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
-    "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
-    document are to be interpreted as described in RFC 2119 (see
-    <a href="#RFC2119">[RFC2119]</a>). However, for readability, these words
-    do not typically appear in all uppercase letters in this specification.</p>
-
-  <p>Additional key words, e.g. "User agent (UA)", are defined by CSS 2.1
-    (<a href="#CSS21">[CSS21]</a>, section 3.1).</p>
-    
+  <p>Conformance requirements are expressed with a combination of
+  descriptive assertions and RFC 2119 terminology. The key words “MUST”,
+  “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”, “SHOULD NOT”,
+  “RECOMMENDED”, “MAY”, and “OPTIONAL” in the normative parts of this
+  document are to be interpreted as described in RFC 2119.
+  However, for readability, these words do not appear in all uppercase
+  letters in this specification. All of the text of this specification is
+  normative except sections explicitly marked as non-normative, examples,
+  and notes. [[!RFC2119]]</p>
+
+  <p>Examples in this specification are introduced with the words “for example”
+  or are set apart from the normative text with <code>class="example"</code>,
+  like this:
+
+  <div class="example">
+    <p>This is an example of an informative example.</p>
+  </div>
+
+  <p>Informative notes begin with the word “Note” and are set apart from the
+  normative text with <code>class="note"</code>, like this:
+
+  <p class="note">Note, this is an informative note.</p>
+
+  <p>Conformance to CSS Text Level 3 is defined for three classes:
+
+  <dl>
+    <dt><dfn title="style sheet!!as conformance class">style sheet</dfn>
+      <dd>A <a href="http://www.w3.org/TR/CSS21/conform.html#style-sheet">CSS
+      style sheet</a>.
+    <dt><dfn>renderer</dfn></dt>
+      <dd>A UA that interprets the semantics of a style sheet and renders
+      <span>documents</span> that use them.
+    <dt><dfn id="authoring-tool">authoring tool</dfn></dt>
+      <dd>A UA that writes a style sheet.
+  </dl>
+
+  <p>A style sheet is conformant to CSS Text Level 3
+  if all of its declarations that use properties defined in this module
+  have values that are valid according to the generic CSS grammar and the
+  individual grammars of each property as given in this module.
+
+  <p>A renderer is conformant to CSS Text Level 3
+  if, in addition to interpreting the style sheet as defined by the
+  appropriate specifications, it supports all the properties defined
+  by CSS Text Level 3 by parsing them correctly
+  and rendering the document accordingly. However the inability of a
+  UA to correctly render a document due to limitations of the device
+  does not make the UA non-conformant. (For example, a UA is not
+  required to render color on a monochrome monitor.)
+
+  <p>An authoring tool is conformant to CSS Text
+  Level 3 if it writes syntactically correct style sheets, according
+  to the generic CSS grammar and the individual grammars of each
+  property in this module.
 
   <h3 id="partial-impl"><span class="secno">2.1.</span> Partial and Experimental Implementations</h3>