From Keira Knightley Wavefront Wiki
When you write a Vanity Page, nobody cares.
A Vanity Page is an article about a particular user written by themselves. We severely frown upon modifying your own user articles. Infact, repeated modification of vanity pages (including reverts of changes by other users) will find you promptly delivered a discretionary ban. This is to discourage Wiki-fights and rampant abuse.
Essentially, unless you're really, really, really sure something is invaluable, never write about yourself on the Wiki.