Page History

...

Additional information may be placed in COREF (e.g., CRF page number or name) to further describe the comment's relationship to the parent record. This can only be done if the relationship cannot be represented using the variables RDOMAIN, IDVAR, and IDVARVAL.

For clinical studies only:

...

Timing variables

...

may also be added to the CO special-purpose domain.

As with Supplemental Qualifiers (SUPP--) and Related Records (RELREC), --GRPID and other grouping variables can be used as the value in IDVAR to identify comments with relationships to multiple domain records. The limitation of this is that a single comment may only be related to a group of records in 1 domain (RDOMAIN can have only 1 value). If a single comment relates to records in multiple domains, the comment may need to be repeated in the CO special-purpose domain to facilitate the understanding of the relationships.

...