Warning 

An important messageThis notice has been left for you because another Wikipedia user suspects that, perhaps inadvertently, you may have defamed someone in your contributions. Please recheck your edits. Do not make allegations against someone unless you have provided evidence from a reliable publication, and then make sure you describe the allegations in accordance with our content policies, particularly Wikipedia:Verifiability and Wikipedia:No original research. Don't rely on hearsay, rumours, or things you believe without evidence to be facts, and don't use sources to create a novel narrative. Wikipedia requires reliable sources for all claims. Please see our policy on biographies of living persons.

If you may have inadvertently defamed someone in an article, do two things:
If the material is still there, remove it immediately. You may wish to use an edit summary like "Removing possible defamation" to prevent it from being reverted.
Leave a note via the oversight page saying that you have accidentally included defamatory claims in a named article or articles. Do not repeat the claim(s). The revision(s) containing the material can then be deleted from the page history.