Well, I'd say forget about it. I've never used this and many other attributes OCAF provides, and to understand why they are there one cannot avoid some historical investigationHow and why there is TDataStd_NoteBook in TDataStd ?
What is the purpose of it ?
OCAF documentation is terrible and does not match anyone's expectations for a contemporary product. Being open-sourced is not an excuse here, although I heard such an opinion that if something is free it can be tolerated. Not today. Frankly, if I had no idea how to use OCAF I'd never start using it. But once you familiarize yourself with it, it really starts to shine. To feel more comfortable with it, you might consider wrapping it with your own object-oriented API. I did that in Active Data (asiActiveData lib) and forgot about bare OCAF.I studied the samples provided by the opencascade and the asitus code. I still feel there is a lack of clarity in OCAF documentation. Though I feel I have made progress I am not quite comfortable with using OCAF.