It's a refresher weekend. Designed to refresh what you may have learnt during the 4 other weekends. Take everything you took before or take a chance. Whats the worst that can happen. Did you net get any Joining Instructions. Did your RRMT not brief you.
Recently completed (within the last 6 weeks) a refresher at Pirbright. The idea is to check you are still able to complete your TAB, WHT and Drill for the Bravo input test. There was no field exercise, so sleeping bag and CBRN kit was unnecessary but I still took it along with all the other kit listed on the joining instructions simply because you may need it to make up the weight and you will need bergen or rocket pouches to complete the TAB!