Anonymous outbound (no callerid) call on Zap channel

Hello!

We have Asterisk servers running in several european countries. So we’re able to forward calls via ENUM (e164.org) to the 0800 numbers of this countries. However, calls via ENUM (from unverified sources) to the PSTN should not contain a callerid!

Regular calls from knwon sources should send their cllerids.

How can I supress the callerid on individual outbound calls on Zap channels?

thanks!
Thomas