Manners

I disagree, one cannot define the the way in which people should interact on 'internet forums' with a wide brush, as you are attempting to do here.

There are plenty of (successful, respected and productive) internet forums where the mode of communication is one that would not be acceptable in the real world. (check slashdot, popbitch and even lfgss).

There are also forums on the internet where rudeness is not tolerated and all members are very polite to one another. Most cookery discussion groups that I have seen conform to this model.

The problem is that it is hard to identify which types of forums are which on the cursory glance that it takes to have a look at them, click the register button and then dive in, posting left, right and centre.

If you take LFGSS as an example. It started out as a small bunch of people who actually knew one another, met up and had beers with one another. For a large, but dwindling, set of the current users of LFGSS, the same is still true. Now, such social groupings (mates, for want of a better term) tend to be quite informal with each other and even sometimes rude. It is understood that this rudeness is meant in a friendly way and is even based on respect and mutual admiration.

The problem in the online community is that new people, who you have never met are suddenly involved in conversations between people who actually know each other very well and behave in an apposite manner. This can be quite off putting, if not offensive to the newcomer.

Fortunately, there is a good way around the above problem: Lurk before joining. Read the threads for a while. Get a feel for what type of community it is. If you don't like it then don't join in. Feel free to benefit from whatever passive advice and wisdom you can receive. Possibly even join in to ask specific questions, knowing full well what kind of response you may get.

The analogy for me is of being in a pub, on your own and seeing a group of friends, talking loudly and having a good time. You notice that they are talking about something completely fascinating that you want to talk about. Would you simply go over and start talking to them, without introducing yourself? Without assessing whether they look friendly or like baby-killers? If they are very polite would you talk to them in a coarse, vulgar manner, f'ing and blinding? What about the reverse?

So, no, I don't think that good manners should be the norm for all internet forums in the same way that I don't think there is a single etiquette standard for all forms of human interaction.