A Role Cop is an investigative role that receives the role name of its target. In Normal games, this is "Cop", "Doctor", "Roleblocker, and so forth. There is no indication of the target's alignment; if a Mafia Goon is investigated, they return "Vanilla", although a Godfather will return "Godfather".
In themed games, the Role Cop has been known to return the target's flavor name (e.g. Pikachu), the target's role name (e.g. One-Shot Thundershocker), or both.
Role Cops have been seen aligned with Town and scum, and is actually a somewhat popular Mafia role in games with many power roles.
In some role madness games or in games with multiple scum groups, the condition that Role Cop does not learn its target's alignment is not applied. Role Cops will learn the full role name of their targets. In particularly extreme cases this has been extended to the Role Cop receiving the entire Role PM of its target (with names and chat topic links deleted, of course).
A Flavor Cop is usually a weaker version of a Role Cop, giving hints to someone's role without explicitly naming it.
A Vanilla Cop only gives results in the form of "vanilla"/"not vanilla".
A Role Cop that returns only their target's full role name and not alignment is considered Normal on mafiascum.net. A Mafia Goon or a Serial Killer with no other abilities should give the same result as a Vanilla Townie. In the case of an X-Shot role, the Role Cop should be told how many shots the role started with. not how many shots used/remaining. Trying to investigate an Ascetic role should return "No Result", the same as if the Role Cop had been blocked.
Use and Power
In Normal games, Role Cops are about on par with Trackers in terms of its power - Role Cop does not learn who its target targeted, but Tracker doesn't know what kind of action the target used. In Theme games, Role Cop can be a somewhat unreliable Cop (or perhaps Flavor Cop) depending on how likely it is that the result they got would be attached to one faction or another. Either way, Role Cop is obviously good for shutting down fakeclaims if it lives long enough.
In scum hands, Role Cop is useful for hunting power roles to be killed on future Nights. Its drawback is that it takes an extra Night for the scum to kill someone the Role Cop finds is a power role.