A file added on the venue panel's Content screen whose text the venue already has is no longer added a second time. The screen names the document that already holds it, and you can replace that document with the new file or discard the new one. A file that is mostly the same as one the venue has waits for your decision, with how much of it is the same: replace, add it anyway or discard. When the venue's website is read, a page that repeats a document already in the venue's content is left out, and the read lists it with that document's name. Documents already in the content that say mostly the same thing are listed under Possible duplicates, so you can remove the older one or keep both.