Token	Definition	Example
_pdbx_chem_comp_identifier.comp_id	This data item is a pointer to _chem_comp.id in the CHEM_COMP category.	text
_pdbx_chem_comp_identifier.type	Contains the identifier type.	CAS Reg No. or PUBCHEM, etc.
_pdbx_chem_comp_identifier.program	The name of the program or library used to compute the identifier.	OpenEye OECHEM program, etc.
_pdbx_chem_comp_identifier.program_version	The version of the program or library used to compute the identifier.	v1.2 (numbers)
_pdbx_chem_comp_identifier.identifier	Contains the identifier value for this chemical component..	text