Where can I report someone?

[Tsumetai]

As the title says, where can I report someone on the forums, as in not report one of his posts, but report him to an administrator regarding more serious and sensitive issues than the dude's posts. Do I have to directly PM an administrator or is there any place for this report to be sent to?

[zerb]

Report it to us moderators as we are more likely to help than the admin's - simply because we are more active.