Giraffe stores and organises assumptions in a concept called usages.

Usages allow you to compile a database of standards and assumptions. This allows your team to link the same data to multiple geometries within a project. From giving all the residential buildings the the same buildCost to making all annotations blue.

Giraffe comes with some default usages such as Residential , Road, Basement Carpark and Annotation but you can create your own and copy them between projects. If you copy a geometry from one project to another, the usages will be copied too. See this example here.

The data model behind Giraffe is explained in more detail here.

Every geometry has a usage. That is how Giraffe knows what each geometry it is. Change a usage by selecting the geometry and changing usage.