Tux: Not the canonical reference but in http://www.w3.org/MarkUp/html3/tables.html there is this:

Hint: You can achieve a similar effect to the above by using decimal alignment and using the DP attribute to set the alignment character to a convenient character, for example:

<table>
  <tr align=decimal dp=":">
  <td>
    name: <input name="name" size=18><br>
    card number: <input name="cardnum" size=18><br>
    expires: <input name="expires-month" size=2> /
    <input name="expires-year" size=2><br>
    telephone:<input name="phone" size=18><br>
</table>
[download]

Each line in the table is then indented so that all the colons are positioned under one another.

And yes, Amaya is a reference browser, but that doesn't change it's incompleteness (acknowledged with respect to CSS, for example, at http://www.w3.org/Amaya/Amaya.html at the heading "Support for CSS").

BTW, I have used it and while it sure is painful to do so, I'm not sure I'd characterize myself as a masochist. Excuse me now, while I go back to reading some nearly unintelligible nodes. :-)