Here are the data structures with brief descriptions:
  celprm | Celestial transformation parameters |
| fitskey | Keyword/value information |
| fitskeyid | Keyword indexing |
| linprm | Linear transformation parameters |
| prjprm | Projection parameters |
| pscard | Store for PSi_ma keyrecords |
| pvcard | Store for PVi_ma keyrecords |
| spcprm | Spectral transformation parameters |
| spxprm | Spectral variables and their derivatives |
| tabprm | Tabular transformation parameters |
| wcserr | Error message handling |
| wcsprm | Coordinate transformation parameters |
 wtbarr | Extraction of coordinate lookup tables from BINTABLE |
