"Flaming" is a popular pastime online that many of us enjoy, so I will give you a few tips for appropriate flaming.
A flame is an insulting message, either posted or emailed. Generally the purpose of flaming is to bloat your own ego while ripping your opponent to shreds. Flames are often used as educational messages but you should try to keep in mind that if you are insulting someone chances are good they aren't going to listen to the wisdom you are imparting. Hopefully your other readers will get the message but don't expect your opponent to hear anything beyond the insult.
If you post a flame, you should always try to email a copy of the flame to your opponent. They deserve to know they are being flamed and they deserve the extra time they might need to format a response.
If your flame essentially gives the message that your opponent is not welcome in the newsgroup you are flaming from or that your opponent is posting inappropriately to that newsgroup you should always post it. This is not an acceptable message to send privately. The rest of the newsgroup deserves to know that you have taken it into your head to police the newsgroup and to rip you to shreds if they think you are out of line.
In general using profanity in a flame is not good enough. If someone has irritated you and you choose to respond with a flame, telling that person, "You SUCK and your mother eats SHIT," will not win you many friends primarily because it is boring. If instead, you use your imagination to insult in an educated manner, even those who completely disagree with you will applaud.
Personally, if I've prepared a particularly imaginative flame, I run it through my Word program for spelling and grammar before I post it. It makes me look better if I have not made obvious spelling and grammar errors and the point of flaming is to boost your ego while slamming your opponent for the entertainment value and possible edification of your readers.
It is possible to disagree without flaming. If you want to disagree but are not in the mood to boost your ego by slamming your opponent then do not use insulting phrases or words. Outline your argument politely and back it up with some education and thought.
When you post to a newsgroup, you are joining an ongoing conversation. Generally the rules of etiquette apply with some variations. There is nothing wrong with interrupting the conversation as long as you do not interrupt it with something outrageously stupid. When someone wanders into a conversation to tell everyone, "YOU ALL SUCK," they are being outrageously stupid. What is worse, they are being outrageously stupid in front of thousands of people, many of whom will NEVER forget it.
When someone joins a conversation that is about a specific topic their comments should generally be related to that topic. Walking up to a group of people who are discussing the pros and cons of lying to their kids about Santa Claus and announcing, "Hey guys, didja know the soaps are showing gay guys IN BED?" is rude.
I'd like to add one more tip, if I may. When you feel that yearn to burn, click on that reply button, snip as much extraneous matter as possible from the original message, flex your fingers and set that screen on fire. When you've crafted the ultimate flame, sit back and admire it for a while and store it if possible (my newsreader, for example, has a "Deferred Delivery" option). This gives you a chance to continue reading the NG, finish the thread and make sure that the flamee hasn't already been pulverised and is no longer a fit target for your righteous wrath. Don't ya just hate it when that happens?? If there's nowhere to store your response, you could go for a bag of Cheetos and a hot chocolate or something. When you come back, admire it some more and if you still want to, send that sucker! For myself, I've found that an undelivered flame is nearly as much fun to write and much less likely to embarrass me later on down the line.
Editor's note: See A Netizen's Guide to Flame Warriors for a fun view