• Posting in the wrong forum
• Usually results in being made fun of or having one's question ignored
• Most often seen when paintball questions are posted in the Thoughts and Opinions section (which is considered the non-paintball section of the forum)
  
• Hijacking a thread
• Questions pertinent to an existing thread are fine; taking over someone else's thread or taking it off topic is not
• Bumping ancient threads (generally more than a few weeks old)
  
• This one is tricky and even the older forumers get it wrong occasionally
  
• Bringing back an interesting technical discussion with new or updated information is generally okay
• If you are going to bring back a picture thread just to say how cool something is, it had better be really, really cool
• Bringing back an old thread to ask a question when no one involved in the thread has posted in it for months is just stupid (and annoying)
• Asking questions without researching first
• People who have been here a while have seen certain questions numerous times and know how easy the answer is to find
• There is lots of information saved in older threads that can be accessed through searches
• The search feature is much more useful once you become used to using the advanced search options
• Not using the search feature for basic questions can come across as a lack of respect for the time the experienced forumers put into helping the newer forumers/players  (i.e. if you don't care enough about your question to do a simple search, why should I care enough to answer your inane, simple question?)
  
• Offering technical advice based on guesses or what you have heard
• There are a lot of people on here with years of paintball experience
• If you pull technical answers out of your lower orifice, you will get called on it
  
• And you will probably get your feelings hurt as well
• We tend to view this seriously as bad advice might be believed by new players who could easily damage their equipment or make poor spending decisions because of it (not to mention the legal/safety risks related to some of the idiot advice in the past)
• Not having a sense of humor
• Expect to get picked on for any of the above (or maybe even for no apparent reason at all)
• Don't take it personally, it's generally done in fun and the older forumers are just as rough, and sometimes rougher, on each other

In conclusion, welcome to the forum.  There is a wealth of experience here and I hope everyone new enjoys their time here as much as us old forum fogeys do.

Note that this is not a comprehensive list, I just hit the highlights.  I invite older forumers to add anything they think I missed and the newer ones to chime in with any questions that relate to this topic.