Iwatsu ENTERPROSE-CS Owner's Manual page 269

Room Status
The keys on a Direct Station Selection Unit (DSS) may be programmed to
inform you of the status of your guest rooms. There are nine status
indications:
VACANT-READY (CLEANING CONFIRMED)
VACANT-TO BE CLEANED
VACANT-CLEANED
OCCUPIED (IN ROOM)-READY (CLEANING CONFIRMED)
OCCUPIED (IN ROOM)-TO BE CLEANED
OCCUPIED (IN ROOM)-CLEANED
OCCUPIED (OUT OF ROOM)-READY (CLEANING CONFIRMED)
OCCUPIED (OUT OF ROOM)-TO BE CLEANED
OCCUPIED (OUT OF ROOM)-CLEANED
When the status of a guest room is changed from the OCCUPIED (IN ROOM)
status category to another category the guest room phone will be restricted.
The maid may change the status of the guest room from TO BE CLEANED to
CLEANED by dialing a code from the guest room phone. The supervisor,
after inspection of the cleaning, may change the status of the guest room from
CLEANED to READY (CLEANING CONFIRMED) by dialing a code from
the guest room phone.
HOSPITALITY FEATURES USER GUIDE - 251