Base Infrastructure Schema > naming-guidelines > special terms Edit this page Special Terms in BIS This section contains rules and recommendations [rec.] related to special terms from the BIS upper ontology Model Description Note Rule Model classes must always be suffixes with Model. E.g. FunctionalModel, PhysicalModelException: GeometricModel2d, GeometricModel3d Element Description Note Rule Abstract terms should only appear higher in the inheritance hierarchy than concrete terms. E.g. The term Element is used to suffix some abstract classes. Once Element is dropped from the name – because the class is concrete - it never comes back.User-facing classes are normally concrete and we especially don’t want to add superfluous terms to those. Rec. User-facing classes should not be expressed in abstract terms E.g. Don’t use InformationContentElement when you can use Document RoleElement Description Note Rec. Don’t suffix with Role E.g. Resource, Asset rather than ResourceRole or AssetRole Aspect Description Note Rec. Suffix with Aspect Type Description Note Rec. Use the term Type for real world types rather than Class or Kind E.g. FunctionalType rather than FunctionalClass or FunctionalKind Last Updated: 15 June, 2021