Guardian

undefined:

A guardian is a system member of any origin whose job is to guard the system.

Guardian is a role similar, but not identical, in function to an external protector or scout. A guardian protects the system from external threats, functions as a gatekeeper to the outside, patrols and secures the outer bounds of the inner world or a section of the inner world, searches for and vets new system members, and may also keep system members away from areas of the inner world that are unsafe for them and/or take away memories that may harm other system members.

This term was coined by the Ironwood Collective on Tumblr.