How to create a new field to attach final version of document

[philipf]

Does anyone have any ideas on the cloud version to have a way to indicate a document is a final version.

Background:
- I know you can't create a new attachment field.

- But I need a way in a legal flow board to indicate which one of the plethora of documents is the final version. 

Steps Taken

- looked at plugins and all there is are lables, and not even lables that appear without driving to a new view

- I don't want to create a sub-task for final contract

- looked into sharepoint connectors, but they all ask for edit permissions, we would just want read. 

Any thoughts or ideas are appreciated. Plugins are on the table, but can't find a reasonable solution.