[iaufwg] FITS conventions update

[William Pence]

Lucio Chiappetti wrote:
> On Thu, 9 Nov 2006, William Pence wrote:
> 
>> information on the various types of conventions.  From the Home page at
>> http://fits.gsfc.nasa.gov/ click on "FITS conventions".  This now leads to a 
>   [...]
>> describes all the registered extension names.  Please send me any comments 
>> or suggestions for improvements on any of these pages.
> 
> *) fits_registry.html
> 
>    the page is conforming to what discussed in the past.
>    As a suggestion for navigation improvement (when it will get longer
>    than now) I suggest you make the references to the two main section
>    (third para, just before the big gray HR) clickable links to the
>    section titles, and give an anchor to the titles.

Yes, this page will need to be reorganized once more conventions get added. 
One option would be to just give a one line summary of each convention on 
the top page, with  links to a more detailed page for each convention.
> 
> *) xtension.html
> 
>    It is not fully clear to me the distinction between "Conforming 
>    Extensions" and "Other Registered Extensions", particularly for
>    what concerns COMPRESS and FITS.

The rational for making 2 sections was that the "Other Registered 
Extensions" section lists those that have been registered by name only, with 
no supporting description of what the full set of extension header keywords 
would look like.  The items under "Conforming Extensions" have more 
extensive documentation that describes the header keyword structure.

>    Should we consider an expiry date for (or a way of reclaim) unused
>    (unimplemented) namespace registrations ?

The FILEMARK and VGROUP extension types are probably only of historical 
interest and maybe could be deleted from this list.  DUMP might still be of 
interest, especially since it was supposed to serve a similar purpose to 
FOREIGN.

BTW, does anyone remember the history of the DUMP proposal?  Who suggested 
it, and when?

>    Should we emphasize graphically (colour coding) the status of
>    implementation and usage of the various extensions ?

This would mean we have to agree on a classification scheme (and associated 
colors) for each status or category.  This seems more trouble than it is 
worth to me.

>> 3.  The next convention up for public comment will be the tiled image 
>> compression convention.  Other conventions that I'd like to get to soon are 
>> the CHECKSUM convention, and the HIERARCH and CONTINUE keyword conventions. 
> 
> essentially you are planning to move (some of) the extensions currently in
> fits_local_conventions.html to fits_registry.html, is that correct ?

In most cases, once a convention is entered into the registry it can be 
deleted from the local conventions page.   The local conventions page is far 
from complete of course, and there are other conventions that potentially 
could go into the registry that are not listed there.

Bill
-- 
____________________________________________________________________
Dr. William Pence                       pence at milkyway.gsfc.nasa.gov
NASA/GSFC Code 662       HEASARC        +1-301-286-4599 (voice)
Greenbelt MD 20771                      +1-301-286-1684 (fax)