Library /sys$common/syshlp/sda.hlb DEFINE, /[NO]TERMINATE  *Conan The Librarian (sorry for the slow response - running on an old VAX)

     /TERMINATE causes the key definition to include termination of
     the command, which causes SDA to execute the command when the key
     is pressed.  No carriage return is required.

     /NOTERMINATE specifies that the key definition does not include
     termination of the command.  When the key is pressed, SDA waits for
     a carriage return before executing the command.
     /NOTERMINATE is the default.