We don't have an afterschool program, but do have a summer camp offered in 2-week sessions for a total of 6 weeks at two different campuses. Parents can enroll students for 1 to 3 sessions. We code using our fiscal year and term along with a budget identifier and a number that indicates the campus, time (day), and session number. So a typical code could be 131CP0701: fiscal year 2013, first term, Camp budget, campus/time 07, session number 01. We keep some demographic information such as grade for grouping purposes and run many reports to keep of allergies, waitlisted campers, grouping, tee shirt labels, etc. to keep things organized. We also generate a list of chaparoning parents by registering them separately into "courses" for each of the trips.