Original: In case you did n't know, when you add content to talk pages and Wikipedia pages that have open discussion, you should sign your posts by typing four halfwidth tildes (~ ~ ~ ~) at the end of your comment.
Simplified: Just in case you did n't know, when you post messages on talkpages and Wikipedia pages, you should sign your posts by typing four tildes ("~ ~ ~ ~") at the end of your message.