d attribute has different syntax than property

master/paths.html

@@ -231,6 +231,10 @@ <h3 id="TheDProperty">Specifying path data: the <span class='property'>'d'</span
 If the path data string contains no valid commands, then the behavior
 is the same as the <span class='prop-value'>none</span> value.</p>
 
+<p>When <a>'d'</a> is parsed as an attribute, it is parsed according to the
+  <a href="#PathDataBNF">svg-path</a> <a href="types.html#syntax">EBNF
+  grammar</a>, instead of the CSS grammar given above.</p>
+
 <p>
   For animation, two <a>'d'</a> property values can only be
   interpolated smoothly when the path data strings contain have the
@@ -253,12 +257,40 @@ <h3 id="TheDProperty">Specifying path data: the <span class='property'>'d'</span
   <a href="https://drafts.csswg.org/web-animations/#animation-interpolation">interpolated</a>
   separately <a href="https://drafts.csswg.org/web-animations/#real-number-animation-type">as
   real numbers</a>.  Flags and booleans must be interpolated as
-  fractions between zero and one, with any non-zero value considered
-  to be a value of one/true.
+  integer values clamped between zero and one.
 </p>
 
 </div>
 
+<div class='ready-for-wider-review'>
+
+<h3 id="TheDAttribute">The <span class="attr-name">'d'</span> attribute</h3>
+
+<dl class="attrdef-list">
+  <dt>
+    <table class="attrdef def">
+      <tr>
+        <th>Name</th>
+        <th>Value</th>
+        <th>Initial value</th>
+        <th>Animatable</th>
+      </tr>
+      <tr>
+        <td><dfn id="TermD" data-dfn-type="element-attr" data-dfn-for="path" data-export="">d</dfn></td>
+        <td>"<span class="attr-value">path data</span>"</td>
+        <td>As if not specified.</td>
+        <td>yes</td>
+      </tr>
+    </table>
+  </dt>
+</dl>
+
+<p>
+ The contents of the attribute must match the svg-path EBNF grammar defined below, and errors within the string are handled according to the rules in the Path Data Error Handling section. If the path data string contains no valid commands, then the behavior is the same as if the attribute was not specified.
+</p>
+
+<h3 id="PathData">Path data</h3>
+
 <p>The following sections list the commands that can be used
 in path data strings.  Those that
 draw straight line segments include the <a href="paths.html#PathDataLinetoCommands">lineto commands</a>

master/types.html

@@ -143,7 +143,11 @@ <h2 id="syntax">Attribute syntax</h2>
 unitless length and angles to be used in presentation attribute while
 disallowing them in corresponding property values.</p>
 
-<p class="note">Note that all <a>presentation attributes</a>, since they are
+<p>The <a>'d'</a> presentation attribute is an exception, it is parsed
+  according to the <a href="paths.html#PathDataBNF">svg-path</a>
+  <a href="types.html#syntax">EBNF grammar</a>.</p>
+
+<p class="note">Note that all other <a>presentation attributes</a>, since they are
 defined by reference to their corresponding CSS properties, are defined using
 the CSS Value Definition Syntax.</p>