[Starky]

Per the TTT staff guidelines:
"8. Staff Impersonation
Staff impersonation isn’t really a problem most of the time. Most players are capable of understanding when someone is joking. They can also tell from the tab menu who actually is or is not staff. The only time this should yield a punishment is if the person in question is being completely serious and actually convincing people they are staff. Just gag or mute accordingly until they stop. If they don’t stop after a few warnings it can probably be considered trolling at that point."

Telling them not to do XYZ would be ok I would assume.
Threatening punishment would be considered impersonating staff.
If staff is on just let them handle it.

(Just my 2 cents)

Tronald.. Its a PH staff rule.                                                                                                                                                                                
13. Do NOT impersonate staff.
Warning 1: Verbal/Chat Notification to change name
Punishment 1: Kick
Punishment 2: Permanent Ban
Holy shit that is pretty harsh ^ I am gonna nerf that. *EDIT* Rule has been updated.