Properties defined on a super-class are automatically marked as "Relevant Records", which is the technique to use in Dev Studio to make an App Studio usable rule - defined in a super-class - appear to App Studio users from any of its subclasses.

See Pega Developer Help on Relevant Records for more information.

Note in the screenshots below how Data Model defined on the Collateral class from the webinar appears on its House subclass when the "Reusable fields" option is chosen:

Properties defined on Collateral superclass

Properties defined on House class ("Reusable fields" turned off)

Properties available to House class, including those inherited from Collateral superclass ("Reusable fields" turned on)

Discussion on this topic was sought from the LSA Data Excellence (Pega 8.4) webinar conducted in July 2020. The webinar and its full set of discussions that arose from it are available at LSA Data Excellence: Webinar, Questions & Answers.