Re: [CSS21] [css3-text] Text decoration behavior

Alex Mogilevsky wrote:
> I like the change earlier proposed by Fantasai (although it needs to say what it replaces. I am
> assuming it replaces the sentence that begins with "In determining the position of and thickness
> of text decoration lines..."
> Paul's earlier message suggested replacing "must" with "should" in regards of using a continuous
> line for text-decoration. "Should" still encourages the most-common-case behavior of underlining
> mixed-font text; however "must" is unusually prescriptive and limits the capabilities of UI to
> deal with corner-cases of fine typographic detail (the freedom UAs still have in vast majority of
> the rest of the spec).

"Should" makes the current behavior of varying the underline position
conformant, and I disagree with that. I also disagree with allowing the
default behavior to shift lines by vertical-alignment position. I do not
believe that this behavior should vary across UAs, and I do not believe
shifting the line position for descendants is the expected behavior for
most cases: cases such as footnote markers, chemical symbols, exponents,
variable subscripts, ordinal numbers, and other abbreviations.

As far as fine typography goes, I can see a use case for this behavior
when a descendant element (other than a superscript or subscript) is a
significantly larger or smaller than the surrounding text (e.g. twice
or half the size). However, this is not the common case. In the common
case the font size on one line does not vary by much.

I don't see any good reason to loosen this requirement in CSS2.1. If
we need a "text decoration follows text" mode to make lawyers and
graphic artists doing headline text happy, then we can add a switch
in CSS3 to make the lawyers and graphic artists doing headline text
happy. I'd rather make the chemists and mathematicians and historians
and paragraph typesetters happy first.


Received on Monday, 10 March 2008 20:21:08 UTC