[fitsbits] CROTA keyword

[Thierry Forveille]

William Thompson writes:
 > 
 > I've encountered some FITS files which contain the keyword CROTA to denote a
 > rotated 2D image.  My reading of the FITS standard (forgetting WCS for the
 > moment) is that there really should be two keywords, CROTA1 and CROTA2, 
 > one for each axis.  Is that correct?
 > 
My memory is that having only one CROTA is/was at least tolerated, if not 
explicitly allowed. Certainly you should expect a number of old FITS
files in the wild to only have one CROTA, with the second rotated axis
indicated by the name/physical unit. Slightly messy, I must admit...