Helps to distinguish distinct sections or units within a building or sub-complex.

A distinct and recognisable section within a building complex, identified by its unique number or an identifier differentiating it from others. This identification can be illustrated by numerals, alphabetic characters, or a combination of both.

The second line of an address and provides a continuation of the valid name and number of the street (including floor and business name if relevant) or post office box information.

The first line of an address and provides a valid street number and name (including floor and building name if relevant) or post office box information.