zeromq/pyzmq — pull request #446 by jsbronder (2013-11-27 15:06:27+00:00)
Title: docs:  clarify behavior when no recv callback is registered

Clarify that either on_recv() or on_recv_stream() must have a registered callback before any data will be received from the underlying socket.

This was confusing to me when developing a new application using REQ/REP sockets where I didn't care about the response yet and was trying to send more requests.