Yes! There are only 2 categories of CEU types under RID: Professionals Studies (PS) and General Studies (GS). Under PS, there are extra labels called Specialization Categories, required for people who have specialized certificates. (like an SC:L, for example) It can be helpful to think of these Specialization Categories a sub-labels under Professional Studies.
PPO is a Specialization category under the Professional Studies umbrella. Ethics and Legal are other Specialization labels. (RID does not require specific Ethics credits to be earned in a cycle, but some state licensing/certifications do.)
Everyone who completes PPO labeled projects earns Professional Studies CEUs.
In summary: All PPO Specialization labels on our site earn Professional Studies credit too.