The LOCK and UNLOCK commands enable you to control update access to a group or list so that only operators with the same operator identifier can make changes.
The lock is held on the CSD file and remains in effect across restarts of CICS®. The lock is owned by the user, who is identified by a combination of the CICS generic applid (specified by the APPLID system initialization parameter), and the user's operator identifier (OPIDENT).
The lock can be removed, using the UNLOCK command, only by a user on the same system and with the same operator identifier.
It would be wise to put a lock on your group of TYPETERMs and on your group of AUTINSTMODEL TERMINALs.