I am having problems with numerous hidden named ranges being introduced to files when a tab containing those names are moved into a new file. The named ranges don't have a functional purpose and originated with files we received from a service provider. The named ranges bog down the file performance. I downloaded a name manager tool that is effective (but slow) in removing the names. However, I really need a way to prevent users from copying an "infected" tab into a new workbook in the first place so this stops spreading. Any ideas? I thought I had this wiped out previously and asked users to be mindful, but now the ranges are back anyways and I think it will continue to be that way until an actual mechanism to prevent it is put in place.