grow your wiki
This pattern refers to the common practice of requiring users to register to edit wiki pages, yet not tying the registration to any meaningful authenticator---just to a password. The result is a wiki that is vulnerable to vandalism and wiki spam, is vulnerable to identity spoofing and other things, yet requires users to create a password-protected identity for their first edit and to log on for subsequent edits.
One way is to adopt an Open-Edit policy, allowing anybody to edit the wiki without registering, and employing alternative effective measures to combat spam.
Another is to provide an incentive for registering, such as a personal profile space, which gives a person space on the wiki to tell about her/himself, and allows them more flexibility in using the wiki than just contributing to the community space.