d attribute has different syntax than property

master/paths.html

@@ -230,6 +230,10 @@ <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

master/types.html

@@ -144,7 +144,11 @@ <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>