It is possible to add new revisions to the file (Previewer > File > New Revision).
You will be asked first to select the file that is a new revision. Then modal with additional information will be shown, giving the possibility to give a reason for a new revision, mark it as current and notify users that a new revision will be created. All users with access to previous revisions will gain access to new revisions as well.
Same as for quotes you can switch between revisions and view the list of revisions.