1) There is a minor typo "none of the server" which should be "none of the servers".
2) The usage may need rewording.
3) This could be more clear that the use of the global admin id is "admin" once that DN has been configured and that --adminUID with the admin id should not be used with the interactive dsreplication enable.
User ID of the Global Administrator to use to bind to the server. For the
'enable' subcommand if no Global Administrator was defined previously for
none of the server the Global Administrator will be created using the
Default value: admin
See OPENDJ-2049 for related information.