A while ago, I asked a question on Super User related to spoofing Caller IDs. The question was down voted and closed. It may be deleted (I don't know because I can't find it).

I need to reference the question, but I'm having trouble locating it. I need to reference it because it has some technical information I need (like Telco Protocols and Incoming vs Outgoing PBX requirements and behaviors).

I've tried searching on Super User with user:xxx caller id and user:xxx pbx with no joy. I also cannot get Google to return the result.

Question: How do I search for the closed (and possibly deleted) question within the Stack Exchange network?

For completeness, I am a Stack Overflow power user. I can see deleted questions, so I know they are available.