My first reaction to this document (0.09) was to be upset at some of the mandatory properties.
I think that it just means that a consumer should consider such properties part of the record but has no obligation to do anything with them except keep them in the record and pass them on if the record is ever harvested into another system.
This could be clearer. I would suggest putting it inline in the text; it'll add to the length of the document but will avoid confusion. Something very short at the start of "Mandatory" sections such as "all recievers must consume and store these properties as part of the catalog record"