Custom Predefined Types in bsDD

Hi All,

I would like to define the structure for consistently relating custom IFC Predefined Types to my PDT subjects.

Does anyone recommend a relationship type I should use? Perhaps the custom Predefined Type should be a “subject” concepts type with the relationship is type of PDT “subject” concept type? Or should the custom Predefined Type be a “Classification” concept type?

Thanks for the feedback,