IfcPropertySetTemplate uses the capitalisation QTO_ in the docs. Should be a minor issue - can this be changed to Qto_? Code that people write is case sensitive, and this encourages further mistakes (see the issue with EPset vs ePSet naming for the geolocation guide - which is still unfixed).
Property set templates can form part of a property library used and declared within a project. Depending on the TemplateType the IfcPropertySetTemplate defines a template for:
- “Pset_” - occurrences of IfcPropertySet
- “QTO_” - occurrences of IfcElementQuantity