From IFWiki

Users here means people who have IFWiki accounts and can therefore edit the wiki, as opposed to readers who only read the pages. This limitation on editing the wiki was imposed in an attempt to reduce spam and vandalism.

To become a user you just need to enter your details on the Special:CreateAccount page.

Users may create user pages about themselves if they wish, but this is completely optional. Note that user pages are distinct from articles in the People category. A user page is freeform, mostly unrestricted (spam is still forbidden), and expected to be primarily authored by the user himself or herself. By contrast, People pages are more formal and encyclopedic, subject to the People style guide, and may be edited by anyone (including the person being documented). Some users simply redirect their user page to their corresponding People page; that's okay too.

A separate user group called IFWiki:TrustedUsers exists, whose members are not presented with Captchas when editing pages.

See also: Special:ListUsers