Most publications have each issue of their publication copyrighted (registering the copyright) when it is published, but there are those that do not go to the trouble or expense to do so. If you sell to a copyrighted publication, your piece is protected under the publication's copyright. However, if you sell to an uncopyrighted publication, you need to ask that they carry your copyright notice at the end of your piece. If your material is published in an uncopyrighted publication without that notice, it goes into public domain—meaning anyone can use it or reprint it without your permission or any payment to you. Keep in mind that there are similar dangers involved when you post your writing online.