[ccp4bb] CAQ

[Vin Purp]

Does anyone know what happened to the monomer CAQ? There are several structures 
in the RCSB with this ligand, and it is not in the sketcher/ccp4 monomer 
library (anymore?).  I also found it on the HIC-UP page as CAQ....so it seems 
at one time it used to be in the monomer library, and now is not (why not?).