From: Charles Lindsey (chl@clerew.man.ac.uk)
Date: Tue May 20 2003 - 07:42:24 CDT
In <3EC8F86B.5040002@Sonietta.blilly.com> Bruce Lilly <blilly@erols.com> writes:
>Claus Färber wrote:
>> The correct word, of course, is "column". Not all graphemes have a width
>> of one column but the column width is what matters.
>If "column" is meant to relate to display issues, that's not necessarily
>correct, as display might use a proportional-spacing font, in which case
>"column" has no meaning.
The word we want has to describe the object that will appear on the
display as a single entity (but which might, after I18N has happened,
consist of a base character with added decorations). I agree that column
could be misleading in some contexts. I see that "glyph" and "symbol" have
been suggested, and I would be happy with either if the WG agrees (mildly
prefer "glyph" over "symbol"). Or is there some other standard word which
the Unicode people use? Martin?
>Are the restrictions (on newsgroup name component and overall newsgroup
>name length) in fact related to display issues, or to something else
>(header field line length, look-ahead for processing, server limitations,
>NNTP protocol limits, etc.)? There's no mention of any rationale in the
>Lindsey draft, nor is there any explanation of where the magic numbers
>30 and 71 came from. Neither the numbers nor restrictions come from RFC
>1036.
The '30' was the number the WG settled on to replace the old '14' which is
generally agreed now to be unnecessary. There is no technical reason for
it. It is a matter of convenience and appearance, and it only appears
there as an initial suggestion. Hierarchy administrators are free to adopt
whatever they consider suitable (e.g. uk.* currently allows 20).
The '71' was also agreed by the WG. It relates IIRC to the maximum that
would still allow a newsgroups-line to fit within 79 characters. Again, it
is an initial suggestion for hierarchy admins to work from.
>My ISP lists a newsgroup named
>alt.religion.kibology.the-not-funny-version-where-lee-can-xpost-not-funny-stupid-threads
>which has a length of 88 characters (= octets) including the dots, which is
>longer than the length 71 restriction in the Lindsey draft. That newsgroup
>name also contains the longest component, length 66 octets (= characters),
>which is more than double the 31 limit in the Lindsey draft.
Well an ISP that chooses to carry such a group I would describe as
terminally clueless. But no matter. Nothing terrible will happen. One
expects that sort of joke on alt.*.
>Once we establish what the real limits are, we should document the rationale
>for the limits along with the actual values. Incidentally, the definition of
>POSIX_PATH_MAX (the minimum allowable value of PATH_MAX, viz. 255) in ISO
>9945-1 (1990) is given in terms of bytes, so if that's what imposes the
>bound, then "octets" is the appropriate unit.
The present limts are expressed in characters, because they relate to the
space taken on displays, rather than to limits which break software.
-- Charles H. Lindsey ---------At Home, doing my own thing------------------------ Tel: +44 161 436 6131 Fax: +44 161 436 6133 Web: http://www.cs.man.ac.uk/~chl Email: chl@clerew.man.ac.uk Snail: 5 Clerewood Ave, CHEADLE, SK8 3JU, U.K. PGP: 2C15F1A9 Fingerprint: 73 6D C2 51 93 A0 01 E7 65 E8 64 7E 14 A4 AB A5