css/css-tables/rules-groups-ref.html

<!DOCTYPE html>
<meta charset=utf-8>
<title>CSS reference: legacy table rules attribute</title>

<style>
table { margin: 1em 1em 2em 1em; border-collapse: collapse; }

#a thead, #a tbody { border-block-end-width: 1px; border-block-end-style: solid; }
#b thead, #b tbody { border-block-end: 1px solid blue; }
#c thead, #c tbody { border-block-end-width: 5px; border-block-end-style: solid; }
</style>

<p>Borders between groups should be present:</p>
<table id=a>
 <thead><tr><td>head</td></tr></thead>
 <tbody>
   <tr><td>body</td><td>one</td></tr>
   <tr><td>body</td><td>two</td></tr>
 </tbody>
 <tfoot><tr><td>foot</td></tr></tfoot>
</table>

<p>Borders between groups should be blue:</p>
<table id=b>
 <thead><tr><td>head</td></tr></thead>
 <tbody>
   <tr><td>body</td><td>one</td></tr>
   <tr><td>body</td><td>two</td></tr>
 </tbody>
 <tfoot><tr><td>foot</td></tr></tfoot>
</table>

<p>Borders between groups should be 5px thick:</p>
<table id=c>
 <thead><tr><td>head</td></tr></thead>
 <tbody>
   <tr><td>body</td><td>one</td></tr>
   <tr><td>body</td><td>two</td></tr>
 </tbody>
 <tfoot><tr><td>foot</td></tr></tfoot>
</table>