[fitsbits] Question on angstrom and erg units in FITS standard

[Steve Allen]

On Tue 2014-11-04T20:18:26 +0100, Thomas Robitaille hath writ:
> Thanks for your reply - but just to be clear, are angstrom and erg
> *actually* deprecated in the FITS standard? That is, should a strict
> writer emit a deprecation warning? It wasn't obvious to me whether the
> fact the units are deprecated in McNally 1988 also means that the units
> are deprecated in FITS?

The header of Table 4 says erg and Angstrom (to be strict, note the
capital A) are "allowed".

These rules are somewhat haphazard, in particular note that annum "a"
is allowed and therefore peta-annum "Pa" is an explicit exceptional
forbidden case to avoid ambiguity with pressure measured in pascal "Pa".

If a FITS writer software package wants to be used by the instrument
building teams that I know then it had better have an option for not
emitting warnings for units like "degC" and "degF".

--
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