When a proof is created, tags are automatically created based on the proof’s file name, however if you need to change them you can. As the proof’s owner you can edit proof tags after the proof has been created.
To add or edit proof tags
Click the i icon on the proof tile, or when viewing the proof to open the info pane.
Click view tags.
Click a tag to remove it
Type text followed by a comma or space to add a tag