[This can be a unit designator, such as apartment number, suite number, or floor. There may be several unit designators in an address (e.g., "3rd floor, Appt. 342"). This can also be a designator pointing away from the location, rather than specifying a smaller location within some larger one (e.g., Dutch "t.o." means "opposite to" for house boats located across the street facing houses). ( HL7V3.0 )]
UMLS (HL7) C1550716 Relation/PAR: AddressPartType
Relation/CHD: unit designator
unit identifier