NAME or ID

[Clive Page]

Dear VOTable expert:

I'm a bit confused about the relative importance of the
NAME= and ID= attributes of the <FIELD element.

Section 4.3 of the VOTable document implies that ID is fundamental, though
it stops short of saying that it is required.  It says that if NAME is not
present it defaults to ID, which strongly implies that NAME is optional.

The sample VOTable shown in section 8 has both ID and NAME for each FIELD,
on the other hand the example in section 1.1 shows just NAME and not ID.
Is this legal?  There's another example in section 6.1.1 has an ID
and not a NAME, which seems more likely to be ok.

I came across this problem when using the VOPLOT utility from the Indian
VO, which seems to require NAME but does not care about ID.  With the
defining document apparently somewhat ambivalent about this, such
discrepancies are to be expected.  Would a VOTable guru like to comment?


-- 
Clive Page,
Dept of Physics & Astronomy,
University of Leicester,    Tel +44 116 252 3551
Leicester, LE1 7RH,  U.K.   Fax +44 116 252 3311