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Re: Concerns about the "l" element name <l>

From: Jukka K. Korpela <jkorpela@cs.tut.fi>
Date: Wed, 3 Nov 2004 11:28:52 +0200 (EET)
To: www-html@w3.org
Message-ID: <Pine.GSO.4.58.0411031041040.12454@korppi.cs.tut.fi>

On Tue, 2 Nov 2004, Thomas O'Connor wrote:

> Going off topic a bit: I think the <l> element is a great idea.

It's a bit off topic regarding the Subject line, but surely not for the
list. An element that means 'line' is somewhat odd, since 'line' is a
concept related to visual presentation rather than logical structure. What
is a 'line' in speech, or in Braille rendering, or to an indexing robot?

Moreover, there are control codes (control characters) for line breaks.
One might say that the need for _markup_ for lines originates from the
decision to treat line breaks in HTML source as whitespace that is
indistinguishable from a space. If HTML were designed now, that decision
might be reconsidered; but HTML is (at least for now) on the XML track
that enforces the whitespace principle.

Logically, <l> and </l> rather than <br /> corresponds to the Unicode
approach to line structure, which promotes the use of record start and
record end characters rather than line break characters. It also
corresponds to the similar principle in SGML. But this also means that <l>
and </l> are effectively control characters in disguise, rather than
delimiters of a logical element.

>  I'm now using <br/> less and less, in fact I don't think I used it
> once in recent designs I made as it doesn't have much point.
> <l> will allow for enhanced control via CSS of code, etc. especially
> when say adding line numbers (generated counters).

Yes, but as soon as generated content and counters really start working,
you can use them even on HTML as currently defined - you can use e.g.
the <div> element, or even make a sequence of lines a <ul> and strip off
the list bullets in rendering.

So much as a devil's advocate. On the positive side, the line concept is
not necessarily just physical. After all, poetry is much older than any
writing, and in poems we have "lines" (verse lines), which are reflected
in recitation too, and primarily there. But does this really correspond to
the intended semantics of the <l> element?

Moreover, there's more in <l> than in <div>. (Note that you can use <div>
in present HTML quite well for dividing text into lines, instead of using
<br>.) Not only does <l> imply line breaks before and after; it also
implies that the content should not be broken across lines - that is,
white-space: nowrap, to say it in CSS.

So if we are serious about <l>, instead of just throwing a new ingredient
into the tag soup, a semantic definition is needed. The current draft
says:
"The l element represents a semantic line of text (e.g., a line of verse
or a line of computer code)."
This is mostly just a play with words. "Line of text" does not become a
semantic concept just because you prefix it with the word "semantic". The
examples help a bit, but an example is not a definition.

Moreover,
"Whether the line should wrap or not depends on styling properties of the
element."
gives too much freedom. It means that a browser may freely break lines
without saying anything about it, at least when it decides to ignore
author style sheets. That is, the line structure is broken in a misleading
way.

Here's a quickly souped up suggestion:

The l element indicates a short fragment of text that constitutes a
separate unit, which normally has no independent meaning but belongs
to a wider context. It is typically much shorter than a paragraph.

The l element can be used to indicate, for example,
- a verse line in a poem
- a major part of a postal address, such as street address
- a mathematical or chemical formula
- a fragment of text inside or after a paragraph, when the fragment
  should be considered as separate from the normal flow of text
- a line of computer code when line structure is significant in
  the code language used.

The l element should not be used for a small fragment of text that
has an independent role and meaning, such as a short copyright statement
like "Copyright 2004 Jukka K. Korpela" or contact information such as
"E-mail: jkorpela@cs.tut.fi". If contact information consists of separate
units such as E-mail address and telephone number, then the units can be
marked up as l elements to separate them from each other.

User agents must, by default, render documents so that the structure
indicated by l elements is clearly expressed. In particular, a visual user
agent must by default render each l element so that it appears on a line
of its own. However a visual user agent may divide an l element into two
or more lines, when necessary to make it fit into the available width,
provided that it clearly indicates that continuation lines are present
(e.g., by suitably indenting them). In speech presentation, intonation
or short pauses or both should be used to indicate the structure.
In rendering on a media that allows neither line breaks nor pauses,
such a Braille, special symbols should be used to indicate the
start and end of an l element.

-- 
Jukka "Yucca" Korpela, http://www.cs.tut.fi/~jkorpela/
Received on Wednesday, 3 November 2004 09:29:25 GMT

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