A commodity-based trust share is issued by a trust that holds a commodity or commodity-based assets, is not registered as an investment company, tracks the performance of its reference assets less expenses, and is created and redeemed in specified minimum baskets.
A spot bitcoin ETP is a claim on a trust which is a claim on a custodian which holds the keys. The Gazette follows the money and distinguishes bitcoin from financial claims on bitcoin; this is the category most of those claims are filed under.