[fitsbits] Fits Table Entries Referring to Keywords

[Randall Smith]

I've been writing a X-ray spectral calculation code (given a
temperature between 10^4 and 10^9 K, and a (low) density, calculate
the emitted spectrum), and storing all the requisite atomic data in
FITS files (website at http://hea-www.harvard.edu/APEC).  

I'd like to give detailed references to all of the atomic data, on a
rate-by-rate basis.  The data is stored in FITS binary tables, with a
40 character ASCII column for references.  This is enough to give a
reference for that data that can be reasonably easily parsed by a
human.  What I'd like to do is change this to store the complete,
journal-quality references in the header and then give a lookup value
in the file.  Ie, on a particular line give the reference as "ZS87",
and then in the header somehow list 
ZS87 = "Zhang,~H \& Sampson,~D.  1987, ApJ, 581, 183"

What I'm wondering is, is there any kind of standard for this?  I could
make the ZS87 a keyword with a long string value equal to the full
reference.  However, I'd like to have complete freedom in making up
the lookup value, and that means there could be a conflict between the
lookup value keyword and a real, well-defined FITS keyword.   Or I 
could use COMMENT statements which I could then parse, but this
information is an important part of the file, and relegating it to
"COMMENT" status doesn't seem right either.

Any suggestions?

Randall Smith
rsmith at cfa.harvard.edu