P.D.: Periodic detention, where people who have committed crimes are required to turn up and intervals and do community service type work such as weeding and rubbish/litter collection.
P.D.: Professional development for in-service teachers. Often run by teachers college lecturers. While undergoing this kind of PD, participants feel as if they must have committed a crime to deserve this kind of punishment.
There is a saying in education: Those who can, do, and those who can't, teach. And those who can't teach, work at Teacher's College.