This is a Docman module. 

One of the features is some documents can (and do) require a login. Yes, we have the groups.io account as primary  document storage

The webmeister is also using this as a alternate storage for N.E.M.O but also needs this module for other websites and is testing before starting major upgrades from joomla 3 to 5 because those other sites are extremely dependent on docman usage.

In this set of documents, the original ms-word file for the NEMO bylaws only becomes visible after login.