Dear David

Thanks for your feedback.  Is the below example the correct way that 
sub-sections should be shown in a HTML table?

Just a couple of question:
1. Have I got the <thead> <tbody> elements in the correct location?
2. Will the rowspan cause difficulty for screen readers?
    (http://www.webaim.org/techniques/tables/2#spanned )

You are right in that I didn't use <th> for the sub-section headings in 
my first example when I should have.  This was because of my 
misunderstanding of the <th> element.  Whilst the sub-section headings 
are "header information" I think I was wanting to distinguish between 
the table headings (what I see as level 1) and table sub-headings (level 
2) using the <th> doesn't show this distinction.

I guess also when I'm creating tables in a word processor I don't put an 
extra column down the left hand side.  I format them as I formatted my 
first example.  I thought using the <caption> would allow people greater 
flexibility possibly through using CSS2 caption-side.

Kind regards,
Scott Rippon.

<table
   summary="This table is an example of a table containing subsections.
   In our example the 2 sub-section each contain sub-section headings.">
   <caption>
    Example Table
   </caption>
   <thead>
     <tr>
       <th scope="col">&nbsp;</th>
       <th scope="col">Table Heading 1</th>
       <th scope="col">Table Heading 2</th>
       <th scope="col">Table Heading 3</th>
     </tr>
   </thead>
   <tbody>
     <tr>
       <th rowspan="2" scope="row">Sub-section Heading 1</th>
       <td>S1C1R1</td>
       <td>S1C2R1</td>
       <td>S1C3R1</td>
     </tr>
     <tr>
       <td>S1C1R2</td>
       <td>S1C2R2</td>
       <td>S1C3R2</td>
     </tr>
     <tr>
       <th rowspan="2" scope="row">Sub-section Heading 2</th>
       <td>S2C1R1</td>
       <td>S2C2R1</td>
       <td>S2C3R1</td>
     </tr>
     <tr>
       <td>S2C1R2</td>
       <td>S2C2R2</td>
       <td>S2C3R2</td>
     </tr>
   </tbody>
</table>