What I see in Google seems that they want you to generate some kind of document that they can ingest in a network. All what i found is about Data Packaging, Network Protocols Games Programing and that kind of stuff.
There is an application that can read these files in Mac OS X, but I don't think you can generate them in a Mac.
[Jean-Christophe Boulay]"I've heard "cap files" used as shorthand for "capture files", which would simply be video. Could that be it?"
it seems that is about capturing any kind of data from a network.