As far as I can tell this isn't in the formal list of rules. A newer player would have no idea whether or not this is an acceptable thing to do or not. Perhaps also a "no sleuthing" rule as well. While I've been told in the past that these rules are "common sense", they're not rules commonly found on other NWN servers (because they're not typically needed to be!). EFU has a unique structure to it and has a unique set of rules and ethic set and they should be as transparent as possible.
Just a heads up, there already is a "no sleuthing" rule!
Quote(42) All players, former-DMs, and current DMs have the right to fairly play characters anonymously. The practice of sleuthing out who plays who is completely forbidden.