Yealink SIP-T48G - Manual (Page 133)

Basic Call Features
123
To place an anonymous call:
1. Using the specific line on the phone to place a call to phone B.
The touch screen of phone B prompts an incoming call from anonymity.
You can use anonymous call rejection to reject incoming calls from anonymous callers.
Anonymous call rejection automatically rejects incoming calls from callers who
deliberately block their identities and numbers from showing up. Anonymous call
rejection is configurable on a per-line basis.
To configure anonymous call rejection via phone user interface:
1. Tap ->Call Features->Anonymous.
2. Tap the desired line.
3. Tap the On radio box of the Anonymous Rejection field.
4. (Optional.) Enter the anonymous call rejection on code in the On Code field.
5. (Optional.) Enter the anonymous call rejection off code in the Off Code field.
6. Tap the Save soft key to accept the change or to cancel.