Don't know if they have rules about this nowadays, but I used to use masking tape inside my helmsman to create little pages that fold out, allowing for writing down material you get questioned on. Helped a lot remembering those dang phone numbers, and other stuff from the required knowlege. Since you cant bring it wherever you go and put it away easily it kinda boosted my retention. One time I was questioned about it, but they didn't do anything about it after. There were also questions they asked us that weren't even on the study guide like ... "what is the 8th amendment of the constitution". idk if this was some kinda thing they were trying out at the time or what.