I do not know if this is possible in other softwares but it is with vBulletin so do you lock the birthday so your users can't changes it? Why do you do what you do?
Yea like you said Paul not really any reason for locking it but then again no reason for an user to changes the birthday either since you can't change when your borned.
I've had a few instances where someone would put in a fake birthday because they didn't think it mattered, then find themselves unable to post or get their birthday greetings from the members on the wrong day. They have to explain themselves to me in order to get it changed.
Most likely not, no - I don't really see the point in using such a feature (at the moment). There's no real (valid) reason for a member to suddenly change their birthday, but it's always possible that a mistake was made during the registration process. ... that said, I could always enable such a feature and have members contact me, if that's the case.
I don't know if it is enabled or not on my forum, as I really don't mind. As long as users are 13+ years old (and if not, have submitted proper documentation) then I don't mind if they change their birthdate every single day. I don't see a reason to lock it, really.
Where do you turn this on, user reg options? I havent come across it as of yet. It still wont stop users re-signing up just to see more mature content.
I think this is off as default in vBulletin. Haven't messed around with the settings for an while but if I remember correctly it is turned off.