Tim has blogged in the past about naming and shaming faculties who do not keep open channels of communication with faculty candidates, particularly those who don't let candidates know if they're: (a) still in the running; or, (b) out of the game as the faculty proceeds with other candidates.
One question that has come up in the past on our own appointments committee is how specific the information should be that an appointments committee gives to candidates throughout the process, particularly if it is a lengthy process for whatever reason. In some years we have had committee chairs let candidates know that they obtained a positive committee vote, and that the candidacy will be moving forward to a faculty vote, and in some years we haven't done that. There may also be cases where, say, the committee is still waiting for external references to come in and won't take a final vote until that happens.
I'm interested in whether other schools have established policies about what to communicate to candidates at what points in the process prior to the actual faculty vote, or whether it tends to be more on a case by case basis depending on the circumstances.