It seems that this rule isn't followed and the moderators could care less. I guess the rules are just made to laugh over here? Even reporting posts doesn't seem to have done anything. Remove the rule if you don't wish to enforce it, or enforce it especially if its reported.
Actually, reported posts that come to our attention are generally edited or deleted, so you wouldn't actually see them once we get to them, so its only natural you don't see them being affected on a regular basis if you miss them, and I can see in the mod tools that several such posts have been dealt with in the last week.
I don't see any reports in the que from you, what exactly is it you wish to report on?
(And checking your post history, one of the people you complained about a month ago was banned, so…)
Bear in mind that "don't spoil the anime section" is more of a polite guideline than a hard rule, but nearly impossible to actually police given how much of the forum reads the manga, in terms of avatars, signatures and such, and that the anime is a full year behind, but we do attempt to deal with whatever is reported.
But it DOES need to be reported, the staff can't be everywhere at all times.
The manga spoilers are cracked down on much more regularly due to timing of release.
Please, if you you have an actual report to make, use the report function, and don't bump 7 year old threads.