definition
strict definition
usage level
The importance of an intended function within a place, distinguishing main purposes from subsidiary ones.
Each usage in a place or object is assigned a usage type, depending on whether it constitutes the main purpose or a subsidiary purpose.
A place can have more than one intended function, with different degrees of importance. The function itself and its importance within the place are separate aspects.
A primary use contributes to the place's main purpose, while a secondary use is subsidiary. Their detailed area conditions distinguish those degrees of use.