Three layers

  1. Open password: File → Encrypt → Password, nothing opens without it;
  2. Editing restriction: Restrict editing → form filling only, readers cannot change text;
  3. Share rights: share cloud documents as read-only with a password and expiry.

Watermarks

Insert → Watermark to add Confidential or Internal use only text, or a custom image — screenshots stay traceable.

Careful

Send passwords through a separate channel. Lost passwords cannot be recovered, so store a hint or use a password manager.