Element Scheme Settings - obscure criterion?

[alexliz23]

I can't seem to find documentation on how to use the 'is in branch of' when it comes to Window/Door Element Schedules. The criterion shows in the pre-canned Schedules but I can't fathom how it works, nor can I add to a new Schedule which I am creating. Any tips will be much appreciated.

 

 

I have stumbled on this thread:

https://community.graphisoft.com/t5/Documentation/Schedule-Criteria-based-on-if-element-is-Classifie...

which I suspect is related to a degree, with @Barry Kelly's reply. However, it's locked and I couldn't reply there to take it further.

[alexliz23 · Accepted solution]

UPDATE - Got it, I needed to go to Add Criteria... > Classifications and add a classification system. It then offers the 'is in branch of' option.