Closely related to DOCS-11283.

SERVER-29182, included in MongoDB 3.6, added authenticationRestrictions info to the output of the usersInfo command (and by extension, the db.getUsers() helper) if the parameter "showAuthenticationRestrictions: 1" is included in the request.

e.g.

db.getUsers({showAuthenticationRestrictions: 1});
db.runCommand({usersInfo:1, showAuthenticationRestrictions: 1});

The current manual pages for these commands do not list this new argument.