How to block incoming calls to some extensions?

Running * 1.6…

I need to block incoming calls from the ptsn to certain extensions. Can anyone give me some tips on how to do this?

Use GotoIf()

Have two contexts, one for calls to extensions that can have external callers, and one for other extensions. Include the former in both the latter and the context used for incoming calls. Use the former as the context for internally originated calls.