"Flame wars" is a term used to describe repetitive abuse being thrown towards one another by two or more users in one thread, with little or no reasoned debate evident.
If you simply MUST trade personal insults with a fellow forum user, we have a PM function. Use it. Alternatively (and preferably) exchange addresses, do it over e-mail and keep it off the forums altogether.
If a thread becomes totally derailed by two or more parties insulting each other repeatedly with no regard for the thread topic, all parties involved will be banned for 2 weeks.
Note that, depending on the severity of the abuse, the ban length may be increased (or even made permanent) at the discretion of the moderating team.