Update index.html

simplifying author's should back to just -1 for indeterminate.  core aam / User agents will be where other values are accounted for.

index.html

@@ -12907,7 +12907,7 @@ <h2>Definitions of States and Properties (all aria-* attributes)</h2>
 				<p><a>Defines</a> the number of items in the current set of items, such as listitems, treeitems, options, comments, etc. Not required if all elements in the set are present in the <abbr title="Document Object Model">DOM</abbr>. See related <pref>aria-posinset</pref>.</p>
 				<p>This [=ARIA/property=] is marked on the members of a set, not the container element that collects the members of the set. To orient the user by saying an element is "item X out of Y" or similar, the <a>assistive technologies</a> would use X equal to the <pref>aria-posinset</pref> <a>attribute</a> and Y equal to the <code>aria-setsize</code> attribute.</p>
 				<p>If all items up to the current item in a set are present in the document structure, it is not necessary to set this <a>attribute</a>, as the <a>user agent</a> can automatically calculate the position for these items. However, if all previous items in the set are not present in the document structure at a given moment, the author MUST set this <a>attribute</a>to provide an explicit indication of an element's position.</p>
-				<p>When specifying <code>aria-setsize</code>, authors MUST set the value to an integer equal to the number of items in the set. If the total number of items is unknown (indeterminate), and the DOM is currently incomplete such that user agents would not be able to compute the correct number of items in a set, authors SHOULD set the value of <code>aria-setsize</code> to a negative number (e.g., <code>-1</code>) or <code>0</code>.</p>
+				<p>When specifying <code>aria-setsize</code>, authors MUST set the value to an integer equal to the number of items in the set. If the total number of items is unknown (indeterminate), and the DOM is currently incomplete such that user agents would not be able to compute the correct number of items in a set, authors SHOULD set the value of <code>aria-setsize</code> to a <code>-1</code>.</p>
 				<p>When specifying <code>aria-setsize</code> on a <rref>menuitem</rref>, <rref>menuitemcheckbox</rref>, or <rref>menuitemradio</rref>, authors SHOULD set the value of <code>aria-setsize</code> based on the total number of items in the <rref>menu</rref>, excluding any separators.</p>
 				<p>The following example shows items 5 through 8 in a set of 16.</p>
 				<pre class="example highlight">&lt;h2 id="label_fruit"&gt; Available Fruit &lt;/h2&gt;