Talkgroup Lockout - GRE PSR-600 Owner's Manual

Applying search lockout to an undesired frequency adds that
frequency to the Search Lockout List, a list of frequencies that
the scanner ignores when performing searches or during
Spectrum Sweeper operations. You can edit or clear the Search
Lockout List by following these steps:
Press
Press the GLOB softkey
Scroll down to the SRCH L/Outs: item and press
Scroll to the frequencies you wish to remove from the lockout list
and press the Del softkey to remove them from the list.
Scroll to an empty spot and enter any frequency you wish to
manually add to the list.
Press FUNC, then the Del softkey to clear the entire list.

Talkgroup Lockout

Talkgroup lockout is similar to search lockout, as it allows you to
lockout undesired talkgroups while searching for new talkgroup
activity with wildcard TGRP objects.
To apply lockout on an undesired wildcard hit, press the TGL/O
softkey while the scanner is stopped on the undesired talkgroup:
PSR-600 User Manual Page
PGM
SEL
64