VMS Help MERGE, Specification File Qualifiers, /INCLUDE, Qualifier Values  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 CONDITION=condition-name

    Refers to the condition-name specified in a previous /CONDITION
    qualifier.

 KEY=...

    Defines a key field because the default record type defined in
    the /KEY qualifier is not being used.

 DATA=...

    Defines a data field because the default record type defined in
    the /DATA qualifier is not being used.