Forum OpenACS Q&A: Re: Defining a skinny, new acs-object type
It's just odd to see a different (seemingly more general) paradigm of acs_object_type__create_type in practice instead of the one in the tutorial / doc. And it appears to have been around since circa 2000, but the only documentation appears to be in api-doc's PL/SQL section.
The question is boiling down to:
When to use acs_object_type__create_type vs content_type__create_type ?