Thread:Project:Support desk/A robust spam-proof system of user registration

Once my site had the feature that new users could register themselves. But even though there was a captcha, this led to a big amount of spam.

Because of spam I have disabled user self-registration.

Now I want to create a semi-automatic system which could work as follows:

When a user registers, he should write in a free text the reason why he want to join editing the site.

This triggers an email sent to moderators (users with a special permission), and a moderator manually allows a user to be added (provided that the user wrote a good "reason why he want to join editing the site"). Meanwhile a password should be generated.

Last, I want Google AdWords to count as a conversion, when a user sends request for account creation.

I know PHP, but not MediaWiki internals. Could you suggest where to start?