W3C home > Mailing lists > Public > www-html@w3.org > March 1999

Re: Dynamic Font Size

From: Jukka Korpela <jkorpela@cc.hut.fi>
Date: Tue, 23 Mar 1999 18:59:23 +0200 (EET)
To: www-html@w3.org
Message-ID: <Pine.OSF.4.10.9903231847320.28338-100000@beta.hut.fi>
On Tue, 23 Mar 1999, Alan G. Isaac wrote:

> Why is it &emsp; and &ensp; but   &mdash; and &ndash; ?

No special reason. I suppose they come from entity names listed
in the SGML Handbook. I don't see any reason why future
HTML specs could't add &emdash; and &endash; as synonyms
for &mdash; and &ndash;. They are just named constants, so to say. 

> Why are  &mdash; and &ndash; equivalent to &#8212; and &#8211;
> instead of &#151; and &#152; ?

Because characters EM DASH and EN DASH occupy positions 8212 and
8211 in Unicode and ISO 10646, wheras code positions 151 and 152
are reserved for control characters in those standards and
therefore &#151; and &#152; are undefined in HTML.

> Why are no character entity references below &#160; listed on
> this page?

There are some, but you probably mean &#n; for n from 130 to 159.
All those references are undefined in HTML.

In HTML, &#n; means the character which occupies code position n
in Unicode; if no such character exists, &#n; is undefined.
Unfortunately some browsers get this wrong, interpreting n in &#n;
as relative to the encoding specified for the document. This is
fundamentally wrong by current specs. I don't think changing
the specs would improve the situation; rather, it would confuse
things more and impose serious restrictions. (Currently, by the
specs, you can include _any_ Unicode character into your document
even if its encoding is plain ASCII, for example.)  

For background explanations, see

Yucca, http://www.hut.fi/u/jkorpela/ or http://yucca.hut.fi/yucca.html
Received on Tuesday, 23 March 1999 11:59:36 UTC

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