[iaufwg] Registering the FOREIGN extension name

[forveill at cfht.hawaii.edu]

On Thu, October 5, 2006 2:49 pm, Mark Calabretta wrote:
> However, in this discussion and the one on
> fitsbits there seems to be some confusion between "convention" and
> "standard".  In my opinion this is the only status that matters; there
> needs to be a clear operational distinction between the two.
I am on the same line here: we should by all means avoid any
misunderstanding that the conventions have any "official"
status. They are something that somebody uses/used and it's
good that they are documented, but given the very loose standard
(essentially some decent description) for "accepting" a convention
the distinction must be made very clear.

> How about
> this for starters:
>
> FITS "standards" define syntax and semantics that are intended to be
> supported by general-purpose FITS interpreting software (e.g. CFITSIO,
> WCSLIB, etc.).
>
>
> FITS "conventions" are based on FITS standards.  They add new
> semantics that are supported by special-purpose software but will not
> generally be understood by general-purpose FITS interpreters.
>
Looks good to me.

> FITS standards and conventions may define a keyword/keyvalue
> namespace that must not be reused with a different meaning in any
> conforming FITS files.
>
Here I'd distinguish between standards (plus standard conventions)
and conventions: the namespace from standards is truely reserved
and must not be reused, while that from plain conventions should
just be avoided as much as reasonable. We don't want one brain-dead
historical convention defined by one guy in an obscure corner to
block FITS evolution, if that case ever occurs :-)