Jamie, I don't envy your role here one bit!!

I have to agree that text speak is infuriating and very difficult to decipher at times...I also completely get Stez's point of people not bothering to answer if they feel you are more articulate and so might not value their efforts...and how important it is that a forum like this is inclusive, rather than exclusive..
I do agree that its important that no one feels alienated here, regardless of how literate or academic they are and everyone should feel free to express themselves without the constant worry about spelling and accuracy.. some things are hard enough to share, without worrying if they are academically correct or not..having said that if it was 'the done thing' to type in text talk on these forums, that would be equally exclusive..if you want to be fully understood then obviously a common and distinguished language is the best approach.
On other forums I have seen similar topics and the emphasis has always been that as an international community, accurate English is essential and the easiest way to ensure that people don't feel left out or unable to participate.
It is difficult as some younger members have learned to type in a time where text/online chatroom speak is considered 'the norm.' but in theory its easier to ask them to type in proper English (as they already should know it vaguely) as opposed to expect older (or less techy) users to learn text speak.
If I may suggest, when I first came here, apart from the suggestion to introduce myself (great idea to get started!) there was no clear way to navigate the boards rules, ethos, essentially how to use the boards/ make the best use of the forums. I've only just realised that the 'index' would be the best place to check (I am by no means simple or inexperienced when it comes to online forums!) But it just didn't stand out to me. A whole bold 'How to use the forum' section would do wonders.
I understand the lack of 'authority' is appealing but on the other hand a clear directive can make people feel more confident and secure.
Perhaps a more defined section, coming from a 'faceless' Havoca leader would promote the guidelines, with the best intentions.. This would also prevent you Jamie from bearing the brunt of making these changes or highlighting these issues, people would feel it was less personal, and for the good of everyone, not just a 'Jamie whim.' (Not that I am suggesting this is a whim or have heard this term used or anything, just pointing out that people respond better to authority if it doesn't have 'a face.' They are more compliant and dont feel personally attacked from one human to another)
It could also prevent people from falling over themselves apologising to you for having an opinion? After all they are not against you and you having an opinion but they may object to your ideas and you have to accept that as 'Jamie the admin', rather than Jamie the person.. I see all the time people being outraged but apologising all in the same breath! (Because they don't want to offend Jamie the person, but disagree with his ideas)
Anyway within that section it could be better explained the importance of not using text speak and explain that it would improve a users experience and feedback if they are better understood.
Here endeth my ramble
