buildingSMART Data Dictionary (bSDD)
The buildingSMART Data Dictionary (bSDD) is a library of object concepts and their properties. It is a service provides by buildingSMART International to help users find the right classifications, properties and values.
The bSDD is an "API-first" service. End-users can access the bSDD through software tools that have implemented the bSDD API. Currently there is a v4 bSDD API and a newer v5 bSDD API. The v5 is also called 'next generation bSDD'. This new v5 is facilitating multiple dictionaries (called 'domains') and Product Data Templates. The v5 is structured according to the new 2020 version of ISO 12006-3.
Read more about the bSDD on https://www.buildingsmart.org/users/services/buildingsmart-data-dictionary/