Recover an account.
This restores your old email address and password if either of these were recently changed. You will be notified by email (to the old email address) if your email or password is changed by you or by someone else. You will be given a reset code to use if this change shouldn't have happened. Note that you can't use this command unless you get a mail from Q giving you a reset code.
Usage: /msg Q RESET username resetcode
For example: /msg Q RESET john 1234abcd
Other help articles under Q Commands