Rule 1 - Admin Authority
Admin powers are only to be used by members authorized to do so. If a member who has not been given admin powers somehow learns of the admin/rcon password(s), he/she is to let an admin know, so the password(s) can be changed.
Rule 2 - Admin Responsibility
All admins are to be respectful, honorable, and just with their admin responsibility. Admins are not to use their powers to tip the scales in a fight, wrongfully agitate or punish players, or to influence the behaviors and gameplay experiences of other players. Admins are to use their powers only to keep order in the server, or to set the stage for a specific gametype/event.
Rule 3 - Password Secrecy
Admins are not to divulge passwords to non-admin (TNA) members. Admins are not to divulge passwords to non-(TNA) members. Admins may only divulge passwords to other admins who may have forgotten the password(s).
Addendum
Although not a rule, it is requested that before making a gametype or map change, the admin wishing to do so polls the people on the server or announces that a gametype/map change will soon be ensuing. The reason for this is that some players may be engaged in specific activites, such as duels, and it would be agitating to have a good fight ended because an admin changed/restarted the map or gametype without warning.
Admins, in short, please keep in mind the gaming experiences of other players on the server, and do not make rash decisions without first thinking about the consequences of your actions.