The AG Wiki is a collaborative project, with lots of different people working together. In order to maintain integrity, we need people to sign up so they and Admin can easily track any changes made to pages.
Having a user name helps you (and everybody else) keep track of your contributions. This way, we all know who's editing and what they're doing, and it helps build a community. Having a user name makes you part of the Wiki. Furthermore, a user name is required in order to make any edits to any pages.
As of July 1st, 2013, compliance with COPPA means that all anonymous editing has been disabled and cannot be re-enabled, due to the focus of the wiki. You are required to create a username in order to edit.
If you have mitigating circumstances, please discuss this with an admin and we will do what we can to accommodate you.