Different Interpretation of "Ad Hominem - Circumstantial"

I notice Irving Copi’s famous book on logic takes a different take on “Ad Hominem-Circumstantial” than almost all other authors including Dr. Bo.    In Copi’s version, an "Ad Hominem Circumstantial" is an argument why someone should believe something, rather than an attack on their views.  The proponent  is suggesting that the listener should believe something because of their circumstances in life.  An example would be to tell a Catholic they must believe abortion is wrong because they’re Catholic. An example Copi gives is to tell a member of the clergy they must accept a proposition because they're clergy, and the denial of that proposition would be incompatible with the Scriptures.  

The more common use of the term “Ad Hominem Circumstantial” is an attack on the other party’s argument by claiming they’re biased because of their circumstances, and therefore their argument is invalid.  

They’re both arguments directed “to the man” and not to the claim. One version is why they should believe a claim because of their circumstances, and the other prejudices the claim because of their circumstances. Both are versions of ad hominem circumstantial.