Could you provide more detail about what you want to accomplish? Are users entering GUIDs as content or in the source of content? Would you want this to flag the content as abusive/spam?
You could make use of censorship to remove GUIDs completely and/or replace them with a message. In Administration > Moderation > Censorship, you can add the following:
You could make use of censorship to remove GUIDs completely and/or replace them with a message. In Administration > Moderation > Censorship, you can add the following:
