I would agree, but I think an even better suggestion would be to have some warnings shown in red at the top of certain sub boards of the most commonly broken rules. Ie:
In the Press section:
Do not post non-bitcoin press articles here.
Gambling:
Do not post ref linksAnd so on. They could be rotated like ads if there's several commonly broken rules.
It's good idea to keep sub-forum/section/child-board keep tidy, but just like any sticky thread (including official rules), it will be ignored.
Whilst many people do ignore them, many also don't. Silly or naive people may not bother reading them, but that's their issue if they don't and they then fall foul of the rules. I know I always familiarise myself with the rules or customs of a forum before I start posting as some are more harsh than others about enforcing rules and bans and warnings/bans can get dished out like candy on some of them.
Why not both? The "unofficial rules" thread for the subforum could help to generate those warnings. Maybe after one ranks up they can have a feature to turn it off or something. I prefer the sticky suggestion simply for the fact it requires no modification of the forum software/structure itself and would be most easily implemented.