First post but please don't take this as a complaint, merely a difficulty that could put off potential new users from registering.
When registering the authentication code is very hard to understand and to the point where I had to reload the page over and over again until I had a code in front of me worth having a crack at. Even then it failed a few times but I persevered because the forum is UK based, like I.
I don't know if anything can be done about it but had a UK based forum not been my criteria on registering I'd have opted for another forum after a few attempts.