Regulated ProfessionsAPELSLAContinuing EducationCurrent List of Educational Activities Preapproved for PDU Credits Professional Development Units (PDU’s) are regulated by 4 CSR 30-8.020. Among other provisions, they allow the Land Surveying Division of the Board to pre-approve a sponsor’s proposed educational activities. Below is the list of future educational activities that have been pre-approved for PDU credits. The current list of approved activities.