Profiles in the CFIELD class
Each profile in the CFIELD class contains a CFDEF segment that defines a custom field and its attributes. Profiles in the CFIELD class are defined and modified using the RDEFINE and RALTER commands. Generic profiles in the CFIELD class are not allowed. Profile names in the CFIELD class must be fully qualified.
In the following examples of profile names, 
DATASET.CSDATA.MYFIELD defines the MYFIELD custom field for data sets,
GENERAL.CSDATA.COMMENT defines the COMMENT custom field for general resources
,
USER.CSDATA.EMPSER defines the EMPSER custom field for user profiles, and
GROUP.CSDATA.COMPADDR defines the COMPADDR custom field for group profiles.
Examples:
DATASET.CSDATA.MYFIELD
GENERAL.CSDATA.COMMENT
USER.CSDATA.EMPSER
GROUP.CSDATA.COMPADDR