RENTAL REGISTRATIONS ARE NOT UNIVERSAL
Each city will have different requirements regarding their rental registration. It can be based on the type of rental, such as if it is a short term rental. Some will require Lead Certification. Some registries will require detailed information about the occupants. Fees and inspections will also vary.
Most city websites will include information about rental registration in their housing/building page.
BENEFITS TO RENTER
A renter in a registered property benefits from higher standard of living conditions. Most cities are require a rental registration also require an inspection. Registration also provides a landlord contact, and increased accountability.
TIP: Whenever possible, before renting, check with the city building/housing to see if they are a registered rental property.