[fitsbits] Questions about the 'REFERENC' keyword.

[Tom McGlynn]

Eric Greisen wrote:
...
>
> Since no one has responded to your question, I will give an answer of sorts.
>
> When the keyword was invented, only one of the concepts listed above was
> even conceivable - a published article citation.  That was the authors'
> intent with the keyword and it would not rule out multiple REFERENC
> keywords with different values for multiple citations.
>
...
 > Eric Greisen
 >
Note that while this is talking about the original standard, the current standard is pretty discouraging for multiple 
REFERENC fields (or any FITS keyword) though they are not forbidden.

 From section 4.1.2.3

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.


Regards,
Tom McGlynn