10.11.6. CLIR on an Individual Subscriber Basis 
When the subscriber specific SDAT attribute SECRAGNT is set,
for calls initiated by this device the following scenarios apply:
- In case of local calls the calling party number is treated as hidden / secret
- In case of external calls, the calling party number is treated as hidden / secret, unless PUBNUM is set for the calling party and the outgoing trunk, in which case the PUBNUM is transported as calling party number.
- If the device is marked as SECRET or has dialed "secret call access code", its number will not be transported at all.
- The parameter can also be used to suppress the display of calling party number in Call Center.