I find this post by the Moderators really really annoying. And I see it for almost all the new users answers.
Welcome to Skeptics! We expect answers to provide references for all significant claims they make. Please add appropriate references to your answer.
If the Mods want to make it clear to the user, think of other (more appropriate) methods to let the user know his answer is not accepted at the site. I am sure after 5 minutes of browsing a person knows how to use the site.
Perhaps a check should be indicated so the user can confirm that his/her answer is unbiased and properly referenced.
Repeating a comment 100's of times is a waste of the Mods time, and makes new users feel unwelcome. (my opinion)