Library /sys$common/syshlp/pca$help.hlb DEFINE, /KEY, Qualifiers, /TERMINATE  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /TERMINATE
       /NOTERMINATE

    Determines whether the current equivalence string is to be
    terminated (that is, processed as command input) when you press
    the defined key. The default is /NOTERMINATE, which allows
    you to enter additional input before the equivalence string is
    processed. Pressing the RETURN key after pressing the defined key
    has the same effect as using /TERMINATE in the key definition.