Grid and Table Properties Guidance: Revise aria-sort subsection

For issue #65, in aria-practices.html,
revised rough draft of the section covering aria-sort.

1. Add note about using on multiple columns.
2. Revisions to wording for accuracy and clarity.
3. Clarified it can be used on rows as well as columns.
4. Correct spelling, grammar, etc.

aria-practices.html

@@ -3888,7 +3888,7 @@ <h2>Grid and Table Properties</h2>
       additionally, some of this information, like skipped columns or rows and how data is sorted, cannot be derived from the DOM structure.
     </p>
     <p>The below sections explain how to use the following properties that ARIA provides for grid and table accessibility.</p>
-    <table>
+    <table class="widget-features">
       <thead>
         <tr>
           <th>Property</th>
@@ -4256,55 +4256,45 @@ <h3>Defining cell spans using <code>aria-colspan</code> and <code>aria-rowspan</
       </p>
     </section>
     <section id="gridAndTableProperties_sort">
-      <h3>
-        Identifying row sorting using <code>aria-sort</code>
-      </h3>
+      <h3>Indicating sort order with <code>aria-sort</code></h3>
       <p>
-        When rows are sorted based on one of the values in one of the columns
-         the <code>aria-sort</code> attribute must be used on the
-        <code>columnheader</code> to identify the column being used to
-        sort the rows of the table or grid.  The following table describes the
-        options for the values of <code>aria-sort</code>.
+        When rows or columns are sorted, the <code>aria-sort</code> property can be applied to a column or row header to indicate the sorting method.
+        The following table describes allowed values for <code>aria-sort</code>.
       </p>
-
       <table class="widget-features">
-        <caption>Description of values for <code>aria-sort</code></caption>
-
+        <caption>
+          Description of values for <code>aria-sort</code>
+        </caption>
         <thead>
           <tr>
             <th>Value</th>
             <th>Description</th>
           </tr>
         </thead>
-
         <tbody>
           <tr>
             <th><code>ascending</code></th>
-            <td>Rows are sorted in ascending order by this column</td>
+            <td>Data are sorted in ascending order.</td>
           </tr>
           <tr>
             <th><code>descending</code></th>
-            <td>Items are sorted in descending order by this column.</td>
+            <td>Data are sorted in descending order.</td>
           </tr>
           <tr>
             <th><code>other</code></th>
-            <td>Rows are sorted by an algorithm other than ascending or
-              descending by this column.
-            </td>
+            <td>Data are sorted by an algorithm other than ascending or descending.</td>
           </tr>
           <tr>
             <th><code>none</code></th>
-            <td>This column is not used for sorting the rows.</td>
+            <td>Default (no sort applied).</td>
           </tr>
         </tbody>
       </table>
-
-      <p>The following example shows using the <code>aria-sort</code> to show
-        that the rows are sorted based on the score of "Quiz 2".   The
-        <code>aria-sort=&quot;descending&quot;</code> identifies the rows being
-        sorted from highest score to lowest score.
+      <p>
+        It is important to note that ARIA does not provide a way to indicate levels of sort for data sets that have multiple sort keys.
+        Thus, there is limited value to applying <code>aria-sort</code> with a value other than <code>none</code> to more than one column or row.
       </p>
-
+      <p>The following example grid uses <code>aria-sort</code> to indicate the rows are sorted from the highest "Quiz 2" score to the lowest "Quiz 2" score.</p>
       <pre>
         <code>
           &lt;table role=&quot;grid&quot; aria-rowcount=&quot;463&quot;&gt;
@@ -4313,11 +4303,8 @@ <h3>
               &lt;tr aria-colindex=&quot;10&quot; aria-rowindex=&quot;1&quot;&gt;
                 &lt;th&gt;Homework 4&lt;/th&gt;
                 &lt;!--
-                  aria-sort is used to identify the column with the heading
-                  "Quiz 2" being used to sort the rows of the grid.  The
-                  value of aria-sort identifies the rows are being sorted in
-                  descending order (e.g. highest score to lowest
-                  score)
+                  aria-sort indicates the column with the heading
+                  "Quiz 2" has been used to sort the rows of the grid. 
                 --&gt;
                 &lt;th aria-sort=&quot;descending&quot;&gt;Quiz 2&lt;/th&gt;
                 &lt;th&gt;Homework 5&lt;/th&gt;