Resident Assistant
These students work for ResEd and are assigned to each residence hall floor. They enforce college policy while carrying out hall meetings on topics such as gendered/non-gendered bathrooms.
They get singles and have some say in what dorm they live in.
RAs will tend to report you for drinking, smoking reefer, having too many people in a room or for other violations.
RAs take their jobs for various reasons, ranging from to a desire to enforce rules to a desire to subjugate them to saving money on housing. As such, they approach their job in a variety of ways. Know what to expect from each one and don't be afraid to approach them with issues. At the same time, know how to avoid them when necessary.
Back when ResEd was still ResLife, RAs were called RCs, for "Resident Coordinator." This term was abandoned, possibly when it was realized how difficult it is to coordinate residents.

