On Wed, 21 Sep 2005, Patricio F. Ortiz wrote:
> As you may pass this email around, I'll write in english.
Thank you. Not all of us are as fluent in XML as we would like.
> I have a concern respect to the case in which column names contain "funny"
> characters ( (), [], ' and ", -, . etc ).
This topic has come up many times before without being properly resolved. The FITS Standard has fairly severe restrictions on column names, which arise because they become header keywords in FITS tables, but nevertheless permits hyphens, a well-known case being DATE-OBS. The hyphen is identical to a minus signs in ASCII, which makes it hard (or impossible) to parse selection expressions involving such columns. The use of hyphens rather than underscores is now deprecated in FITS syntax, I think.
I think the VO world should specify a standard for column names in tables for the future with rules which avoid such problems, but we have to cope with the fact that problem characters are present in existing in tables. Perhaps some standard mapping to permitted characters could be devised?
-- Clive Page Dept of Physics & Astronomy, University of Leicester, Tel +44 116 252 3551 Leicester, LE1 7RH, U.K. Fax +44 116 252 3311Received on 2005-09-21Z11:46:47