[iaufwg] convention or standard

[Mark Calabretta]

On Mon 2006/10/09 18:14:14 +0200, Lucio Chiappetti wrote
in a message to: IAU-FWG <iaufwg at nrao.edu>

Lucio,

>- one is that there are presently two different "registries" involved,
>  one is the convention registry 
>  http://fits.gsfc.nasa.gov/fits_registry.html
>  the other one is the list of registered extensions
>  http://fits.gsfc.nasa.gov/xtension.html

Good point.  Why not amalgamate them, whether tightly or loosely?

There is also an association with the keyword dictionary, of which I
note that TDMAXn, TDMINn, TLMAXn and TLMINn have now ascended into the
convention registry.

>And here the "once FITS always FITS" comes in place. I agree with Bill 
>when he says
>
>> Another point to recognize is that adding a name to this list does not 
>> necessarily reserve that name indefinitely.  For instance, it is very 
>> unlikely that the 'COMPRESS' and 'VGROUP' names will ever be implemented 
>> as originally suggested, so there is no reason not to reuse those names 
>> for another purpose if someone wanted to.

Why bother to register a convention if it doesn't reserve the namespace?
In fact, why bother to have a registry if not to reserve namespaces?

But namespace reservation wouldn't prevent the DUMP, FILEMARK, VGROUP,
or FITS XTENSION names from being "redefined" because they were never
defined or used.  Likewise COMPRESS, which was only a suggestion -
all of these speculative extensions could simply be deregistered now.
However, it does safeguard A3DTABLE and IUEIMAGE (or should do).

Cheers, Mark