Pick one real file you might upload to an AI tool. Check: extra tabs, comments, tracked changes, author metadata. You're done when you've listed what a stranger would learn from the parts you didn't mean to share — or confirmed it's clean.
How-to · INF · INF.5
Upload vs paste — where does the file go?
Uploading a file sends the whole file, not just what you meant; scan for hidden tabs, comments, and metadata first.
Worked example
Pasting sends what you selected. Uploading sends everything — the hidden spreadsheet tab, the tracked changes, the comment thread from legal. Before any upload: open the file and check what's riding along in the parts you forgot existed.