I'll answer that. Admins and up can make up whatever time period their ban covers, as well as how many single infraction points they dish out (not sure about the second one, I mean it sounds logical so it's probably true). So Smods and below need to stick to this catalogue of ways to punish people, which consists of a few infraction points, 1 day bans, 1 week bans, etc. In my experience from clan modding, I mostly talked personally to people I felt were going against the rules and in the case of a continued offence dish out a 1 day ban. But that's just me, clan people aren't exactly known for being the most experienced users so their problems are mostly legitimate lack of knowledge for the rules rather than malice.