Ositech comm Trumpcard Data/Fax Modem User's Manual And Reference page 35

Modem Command Reference
If you enter a parameter for the AT\ or AT% commands that is out of range,
the upper limit is stored and no ERROR message is reported.
Following the modem command description assume OK and ERROR as
valid responses for almost all of the commands. Other valid responses
for a command, if any, are discussed with the command descriptions.
User's Guide and Reference 4 - 3