Jasper Fforde said this quote
“ The Special Operations Network was instigated to handle policing duties considered either too unusual or too specialized to be tackled by the regular force. There were thirty departments in all, starting at the more mundane Neighborly Disputes (SO-30) and going onto Literary Detectives (SO-27) and Art Crime (SO-24). Anything below SO-20 was restricted information, although it was common knowledge that the ChronoGuard was SO-12 and Antiterrorism SO-9. It is rumored that SO-1 was the department that polices the SpecOps themselves. Quite what the others do is anyone's guess. What is known is that the individual operatives themselves are mostly ex-military or ex-police and slightly unbalanced. 'If you want to be a SpecOp,' the saying goes, 'act kinda weird... ”