Text-decoration from Matthew Brealey on 1999-11-24 (www-style@w3.org from November 1999)

From: Matthew Brealey <thelawnet@yahoo.com>
Date: Wed, 24 Nov 1999 04:20:34 -0800 (PST)
To: www-style <www-style@w3.org>
Message-ID: <19991124122034.4466.rocketmail@web901.mail.yahoo.com>

Where exactly should the various text-decorations be
drawn?

For example, should underline go underneath the text,
and hence be unaffected by line-height?

line-through
Each line of text has a line through the middle

Presumably this is a minor terminoligical
inexactitude, since it is ambiguous as to whether
'line' means line box or whether it refers to the
'text box' (that is to say an imaginary box that
encloses the text).

Presumably:
line-through
Each glyph has a line through its middle
...
overline
Each line of text has a line above it.
Where?

Above the line box?
...
T-d spans descendant elements, but is not inherited.

Given
P {t-d: underline; font: 14pt/18pt Arial}
and:
P SPAN {font: 12pt}

Then t-d spans the P, and one can only assume that is
meant to be placed so that the top of the font's
descenders sit on the underline.

As a result, the t-d is placed at an appropriate place
for 14pt, which will be wrong for 12pt, but since the
property is not inherited, the place for 14pt will be
the place that must be used, and thus it will not
underline the SPAN, but wil sort of line-through it.

<q cite="
http://www.w3.org/TR/REC-CSS1#text-decoration ">
E.g., if an element is
underlined, the line should span the child elements.
</q>