Hi @gwynne,
Thanks for your post, we do provide an option for setting a review date on a Document, this will allow you to schedule a date when the document is due to be reviewed and will create an activity against that document to remind you when the document is up for renewal. This can be done by clicking on the Review tab on the document properties page (see screenshot) or by entering a Review Date when creating a document. The review activity will be visible in the activities panel of the document so you can assign, edit or complete the activity easily from within the document page. Hope this helps.
Trevor