[fitsbits] Primary & Alternate WCS Keyword Order

[Lucio Chiappetti]

On Sat, 30 Jun 2012, Mark Calabretta wrote:
> On Fri 2012/06/29 10:55:06 +0200, Lucio Chiappetti wrote

>> What Bill did for the verifier (excerpt below) appears consistent with the
>> LETTER of the standard, which talks only of the position of WCSAXES and
>> not of WCSAXESa
>
> That's only because WCSAXES is introduced in Paper I before alternate
> representations are introduced, so it should follow that what applies
> to WCSAXES also applies to WCSAXESa.

Well ... that the distinction between the LETTER and the SPIRIT of the 
standard :-)

If we'd go too deeply in a literal interpretation we'd have WCSAXES shall 
precede all WCS kwds (including WCSAXESA or WCSAXESK), but also WCSAXESK 
shall precede all WCS kwds (including WCSAXES itself and WCSAXESA !) 
and WCSAXESA shall precede all etc. etc. !!!

If instead we say that the spirit is that each WCSAXESa precedes its own 
WCS kwds (as recommendation) and only WCSAXES precedes all, we could claim 
the standard is complete, and the main s/w (fverify, WCSlib etc.) is 
compliant.

All your suggestions are extremely sensible ...

... I was just trying to understand whether we should make an amendment to 
the standard at this stage (which will be a couple of lines on a 52 page 
document, and will introduce a deviation from the A&A published stuff, 
both Pence et al 2010 and WCS Paper I ... which is "incorporated by 
reference")

... or we could pretend that the standard is clear enough, and issue only 
some sort of explanatory note

... reserving the amendment for the next round (3.1 or 4.0) whenever it 
will be (not too soon hopefully).

Since I see it's already Saturday down there ...
... nice weekend to everybody.