|This page is not a sandbox and should not be used for test editing. To experiment, please do so on Wikipedia:Sandbox or one of the other sandboxes.|
Place holder is an account created to be used when you intend to replace the user name with an actual user later. It also serves in ranked lists of Wikipedians to hold the place of those who do not wish to be listed by name, without invalidating the rankings.
User:Example is a similar account created to be used in examples where you don't want to name a particular user.