At the end of the L4th, pupils are allowed to take part in Combined Cadet Force (CCF), although this is optional until the end of the 5th form when pupils may choose between CCF or the Community Service Organisation (CSO). They are required to take part for the following year (Lower Sixth) on a Tuesday after school. Many continue with CCF in the Upper Sixth as well, but CSO only ever exists in Lower Sixth (until the end of the academic year 2011-2012 it was compulsory to do one or the other in the Upper Sixth also).