#2 - Don't crap on a person's sale ad. In short, this means that anything that might take away from a person's ad should not be posted. Don't tell about how you got yours for $100 less, don't mention that the one you had died after 2 months, don't tell people you "think" their Leupold is a fake because you saw a thread 3 years ago on another site about it and remember that they all should have a gold medallion and don't make lowball offers on the thread.....whatever it is just keep it to yourself or send them a pm. PM's are great for asking a seller a question, making an offer, telling them it might be a clone/fake, etc. PM's are also a great way to save yourself from the public embarrassment of being an ass.