How to sign a trunk in Asterisk?

Question

Asterisk

How to make a custom signature for a trunk? I need the user to be transferred to the sip client the number of the caller and an arbitrary word that determines through which trunk he is being called.
We use different numbers on different sources of advertising and need to respond to them differently.

Answer 1

In FreePBX, in the incoming routing, the Prefix item - write Msk- there and the call will come with the Msk-89068775982 prefix.
For those who like to write by hand exten => s, 1, Set((CALLERID(name))=Msk-${CALLERID(num)})

Answer 2

Pass desired text to CALLERID(name)?
exten => s, 1, Set(CALLERID(name)="MYTEXT")