[fitsbits] DOI keyword usage for FITS? {External}

[Mark Calabretta]

Record-valued keywords, e.g. DPj and DQi as defined in WCS Paper IV,
are multiply defined by design.

As the original FITS specification did not prohibit multiply defined
keywords, the "once FITS always FITS" principle deems that they cannot 
subsequently be prohibited.

I see no reason not to allow multiply defined keywords, provided that it
is known in advance that a particular keyword may be multiply defined so
that header parsing software is prepared for the possibility.

Mark Calabretta



On Thu, 3 Aug 2023 17:18:33 +0000
"Seaman, Robert Lewis - \(rseaman\) via fitsbits" <fitsbits at listmgr.nrao.edu> wrote:

That seems a bit dismissive of the whole notion of DOIs. Also, thoughts about duplicate keywords?


The mandatory FITS keywords defined in this Standard must not appear more than once within a header. All other keywords that have a value should not appear more than once. If a keyword does appear multiple times with different values, then the value is indeterminate.

Rob