There is a Duplicate Button on the left side above the Document Preview.
With this you can duplicate any document regardless of the document state.
The Document Details window opens for the duplicated document, and you can make changes.
Above the Document Preview, there is a Create reminder Button on the left of the button bar to the right of the Duplicate Button (the document icon with the exclamation mark).
With this you can create a reminder for each document: The document is duplicated and changed into a reminder.
The Document Details window opens for the created reminder, and you can make changes.