The aircraft in question are listed as having the reduced MTOW (shows in JP Airline Fleets) and a revised MTOW filled for flights expected to exceed it. Cases of exceeding the reduced MTOW were very rare for us, normally exceptional load (unusually high ratio of males to females combined with large number of bags such as golf clubs). Higher MTOW's are normally routine for the longer sectors such as SSH. The CAA could always spot check, noting ATOW, or request copies of loadsheets. The savings must make the paperwork cost effective as the difference is as much as 12 tonnes for the heavyweights.