Before plunging into the mappings from FITS formats to Asterix interface items a couple of lower level mappings relevant to all FITS files are now given.
Anywhere the user can currently enter an HDS scalar primitive value, a FITS keyword name will also be accepted. Likewise anywhere an HDS array can be supplied a FITS image extension or FITS bintable column can be supplied instead.
Two examples for binned data are given, for spectra and images as well as the mapping for event data.