UTF-8 All The Things

sections/attributes.include

@@ -128,13 +128,13 @@
       <th><code>charset</code></th>
       <td><{meta}></td>
       <td><a>Character encoding declaration</a></td>
-      <td><a>Encoding label</a>*</td>
+      <td><a>utf-8</a></td>
     </tr>
     <tr>
       <th><code>charset</code></th>
       <td><{script}></td>
       <td>Character encoding of the external script resource</td>
-      <td><a>Encoding label</a>*</td>
+      <td><a>utf-8</a></td>
     </tr>
     <tr>
       <th><code>checked</code></th>
@@ -1378,4 +1378,4 @@ complicated than indicated in the table above.</small></p>
         <td><a>Event handler content attribute</a></td>
       </tr>
     </tbody>
-  </table>
+  </table>

sections/changes.include

@@ -24,6 +24,10 @@
         <dd>Change to match reality. Fixed <a href="https://github.com/w3c/html/issues/1212">issue 1212</a></dd>
     <dt><a href="https://github.com/w3c/html/pull/1204">Caption end tag can be ommitted.</a></dt>
       <dd>Substantive change to match reality. Fixed <a href="https://github.com/w3c/html/issues/1158">issue 1158</a></dd>
+    <dt>
+      <a href="https://github.com/w3c/html/pull/1273/">Mandate UTF-8</a>
+    </dt>
+    <dd>Substantive change to match reality. UTF-8 is now mandatory for all new pages. Fixed <a href="https://github.com/w3c/html/issues/1039">issue 1039</a></dd>
   </dl>
 
 <h3 id="changes-wd2">Changes between the <a href="https://www.w3.org/TR/2017/WD-html53-20170206/">HTML 5.3 Second Public Working Draft</a>

sections/iana.include

@@ -37,8 +37,8 @@
       :: The <code>charset</code> parameter may be provided to specify the
           <a>document's character encoding</a>, overriding any
           [=character encoding declarations=] in the document other than a Byte Order Mark (BOM).
-          The parameter's value must be one of the <a lt="character encoding">labels</a> of the <a>character encoding</a>
-          used to serialize the file. [[!ENCODING]]
+          The parameter's value must be an <a>ASCII case-insensitive</a> match for the string
+          "<code>utf-8</code>".
   : Encoding considerations:
   :: 8bit (see the section on [=character encoding declarations=])
   : Security considerations:
@@ -264,8 +264,10 @@
   <dt>Optional parameters:</dt>
   <dd>
     <dl>
-    <dt><code data-x="">charset</code></dt>
-    <dd>The charset parameter may be provided. The parameter's value must be "<code>utf-8</code>". This parameter serves no purpose; it is only allowed for compatibility with legacy servers.</dd>
+      <dt><code data-x="">charset</code></dt>
+      <dd>The charset parameter may be provided. The parameter's value must be "<code>utf-8</code>".
+          This parameter exists only for compatibility with legacy servers.
+      </dd>
     </dl>
   </dd>
 

sections/obsolete.include

@@ -28,6 +28,10 @@
 
   Authors should not specify a <{img/border}> attribute on an <{img}> element. If the
   attribute is present, its value must be the string "<code>0</code>". CSS should be used instead.
+
+  Authors should not specify a <code>charset</code> attribute on a <{script}> element. If the
+  attribute is present, its value must be an [=ASCII case-insensitive=] match for the string
+  "<code>utf-8</code>". [[!ENCODING]]
 
   Authors should not specify a <{script/language}> attribute on a <{script}> element. If
   the attribute is present, its value must be an [=ASCII case-insensitive=] match for the string
@@ -66,6 +70,9 @@
   * The presence of a <{img/border}> attribute on an <{img}> element if its value is the string
     "<code>0</code>".
 
+  * The presence of a <code>charset</code> attribute on a <{script}> element if its value is an
+    [=ASCII case-insensitive=] match for "<code>utf-8</code>".
+
   * The presence of a <{script/language}> attribute on a <{script}> element if its value is an
     [=ASCII case-insensitive=] match for the string "<code>JavaScript</code>" and if there is no
     <{script/type}> attribute or there is and its value is an [=ASCII case-insensitive=] match
@@ -174,6 +181,11 @@
   : <dfn element-attr for="link"><code>charset</code></dfn> on <{link}> elements
   :: Use an HTTP <code>Content-Type</code> header on the linked resource instead.
 
+  : <dfn element-attr for="script"><code>charset</code></dfn> on <{script}> elements 
+    (except as noted in the previous section)
+  :: Omit the attribute. Both documents and scripts are required to use <a>UTF-8</a>. It is
+     redundant to specify it on the <{script}> element since it inherits from the document.
+
   : <dfn element-attr for="a"><code>coords</code></dfn> on <{a}> elements
   : <dfn element-attr for="a"><code>shape</code></dfn> on <{a}> elements
   :: Use <code>area</code> instead of <{a}> for image maps.
@@ -1351,11 +1363,15 @@
 
   <pre class="idl" data-highlight="webidl">
     partial interface HTMLScriptElement {
+      [CEReactions] attribute DOMString charset;
       [CEReactions] attribute DOMString event;
       [CEReactions] attribute DOMString htmlFor;
     };
   </pre>
 
+  The <dfn attribute for="HTMLScriptElement"><code>charset</code></dfn> IDL attribute of the
+  <{script}> element must reflect the element's <code>charset</code> content attribute.
+
   The <dfn attribute for="HTMLScriptElement"><code>event</code></dfn> IDL attribute of the
   <{script}> element must reflect the element's <{script/event}> content attribute.
 

sections/semantics-document-metadata.include

@@ -829,12 +829,10 @@
   The <dfn element-attr for="meta"><code>charset</code></dfn> attribute specifies the character
   encoding used by the document. This is a <a>character encoding declaration</a>. If the
   attribute is present in an <a>XML document</a>, its value must be an
-  <a>ASCII case-insensitive</a> match for the string "<code>utf-8</code>" (and the
-  document is therefore forced to use <a>UTF-8</a> as its encoding).
+  <a>ASCII case-insensitive</a> match for the string "<code>utf-8</code>".
 
-  <p class="note">The <code>charset</code> attribute on the
-  <{meta}> element has no effect in XML documents, and is only allowed in order to
-  facilitate migration to and from XHTML.</p>
+  <p class="note">The <code>charset</code> attribute on the <{meta}> element has no effect in XML
+  documents. It is allowed in order to facilitate migration to and from XHTML.</p>
 
   There must not be more than one <{meta}> element with a <code>charset</code> attribute
   per document.
@@ -1221,10 +1219,9 @@
       This state's user agent requirements are all handled by the parsing section of the specification.
 
       For <{meta}> elements with an <code>http-equiv</code> attribute in the <a state for="http-equiv">encoding declaration state</a>, the <code>content</code> attribute must have a value that is an
-      <a>ASCII case-insensitive</a> match for a string that consists of: the literal string
+      <a>ASCII case-insensitive</a> match for a string that consists of the literal string
       "<code>text/html;</code>", optionally followed by any number of [=space characters=],
-      followed by the literal string "<code>charset=</code>", followed by one of the <a lt="character encoding">labels</a>
-      of the <a>character encoding</a> of the <a>character encoding declaration</a>.
+      followed by the literal string "<code>charset=utf-8</code>".
 
       A document must not contain both a <{meta}> element with an <code>http-equiv</code>
       attribute in the <a state for="http-equiv">encoding declaration state</a> and a <{meta}> element with the
@@ -1417,24 +1414,31 @@
 
   A <dfn>character encoding declaration</dfn> is a mechanism by which the <a>character encoding</a>
   used to store or transmit a document is specified.
+
+  The only acceptable character encoding declaration for the modern web is <a>UTF-8</a>.
+
+  This must be identified by the <a>character encoding</a> label's value being an
+  <a>ASCII case-insensitive</a> match for the string "<code>utf-8</code>".
+
+  Regardless of whether a character encoding declaration is present or not, the actual character
+  encoding used to encode the document must be <a>UTF-8</a>. [[!ENCODING]]
 
   The following restrictions apply to [=character encoding declarations=]:
 
-  * The character encoding name given must be an <a>ASCII case-insensitive</a> match for one of the
-      <a lt="character encoding">labels</a> of the <a>character encoding</a> used to serialize the file. [[!ENCODING]]
   * The character encoding declaration must be serialized without the use of
       <a>character references</a> or character escapes of any kind.
   * The element containing the character encoding declaration must be serialized completely
       within <dfn>the first 1024 bytes</dfn> of the document.
+  * Due to a number of restrictions on <{meta}> elements, there can only be one
+      <code>meta</code>-based character encoding declaration per document.
 
-  In addition, due to a number of restrictions on <{meta}> elements, there can only be one
-  <code>meta</code>-based character encoding declaration per document.
+  Authoring tools must default to using <a>UTF-8</a> for newly-created documents. [[!ENCODING]]
 
   If an <a>HTML document</a> does not start with a BOM, and its <a>encoding</a> is not explicitly
-  given by <a>Content-Type metadata</a>, and the document is not <a>an `iframe` `srcdoc` document</a>, then the character encoding used must be an
-  <a>ASCII-compatible encoding</a>, and the encoding must be specified using a <code>meta</code>
-  element with a <code>charset</code> attribute or a <{meta}> element with an
-  <code>http-equiv</code> attribute in the <a state for="http-equiv" lt="content-type">encoding declaration state</a>.
+  given by <a>Content-Type metadata</a>, and the document is not <a>an `iframe` `srcdoc` document</a>,
+  then the encoding must be specified using a <code>meta</code> element with a <code>charset</code>
+  attribute or a <{meta}> element with an <code>http-equiv</code> attribute in the
+  <a state for="http-equiv" lt="content-type">encoding declaration state</a>.
 
   <p class="note">
     A character encoding declaration is required (either in the <a>Content-Type metadata</a> or
@@ -1449,23 +1453,8 @@
 
   If an <a>HTML document</a> contains a <{meta}> element with a <code>charset</code>
   attribute or a <{meta}> element with an <code>http-equiv</code> attribute in the
-  <a state for="http-equiv" lt="content-type">encoding declaration state</a>, then the character encoding used must be an
-  <a>ASCII-compatible encoding</a>.
-
-  Authors should use <a>UTF-8</a>. Conformance checkers may advise authors against using legacy encodings.
-  [[!ENCODING]]
-
-  Authoring tools should default to using <a>UTF-8</a> for newly-created documents. [[!ENCODING]]
-
-  Authors must not use encodings that are not defined in the WHATWG Encoding specification. Additionally,
-  authors should not use <a>ISO-2022-JP</a>.  [[!ENCODING]]
-
-  <p class="note">
-    Some encodings that are not defined in the WHATWG Encoding specification use bytes in the range 0x20
-    to 0x7E, inclusive, to encode characters other than the corresponding characters in the range
-    U+0020 to U+007E, inclusive, and represent a potential security vulnerability: A user agent
-    might end up interpreting supposedly benign plain text content as HTML tags and JavaScript.
-  </p>
+  <a state for="http-equiv" lt="content-type">encoding declaration state</a>, then the character
+  encoding used must be <a>UTF-8</a>.
 
   <p class="note">
     Using non-UTF-8 encodings can have unexpected results on form submission and URL encodings,

sections/semantics-scriptings.include

@@ -135,15 +135,6 @@
   <{script/async}>, <{script/defer}>, <{script/crossorigin}>, and <{script/integrity}> attributes must
   not be specified.
 
-  The <dfn element-attr for="script"><code>charset</code></dfn> attribute gives the character
-  encoding of the external script resource. The attribute must not be specified if the
-  <{script/src}> attribute is not present, or if the script is not a <a>classic script</a>.
-  (<a>Module scripts</a> are always interpreted as UTF-8.) If the attribute is set, its value
-  must be an <a>ASCII case-insensitive</a> match for one of the
-  <a lt="character encoding">labels</a> of an <a>encoding</a>, and must specify the same
-  <a>encoding</a> as the <code>charset</code> parameter of the <a>Content-Type metadata</a> of the external
-  file, if any. [[!ENCODING]]
-
   The <dfn element-attr for="script"><code>async</code></dfn> and
   <dfn element-attr for="script"><code>defer</code></dfn> attributes are <a>boolean attributes</a>
   that indicate how a script should be loaded and executed.
@@ -204,7 +195,6 @@
   The IDL attributes
   <dfn attribute for="HTMLScriptElement"><code>src</code></dfn>,
   <dfn attribute for="HTMLScriptElement"><code>type</code></dfn>,
-  <dfn attribute for="HTMLScriptElement"><code>charset</code></dfn>,
   <dfn attribute for="HTMLScriptElement"><code>defer</code></dfn>, and
   <dfn attribute for="HTMLScriptElement"><code>integrity</code></dfn>, must each <a>reflect</a> the
   respective content attributes of the same name.