After a successful installation, plagued initially by corruption of the FTP process (overcome by doing a careful comparison of the unzipped download file name with their copies on the web, dragging them missing ones into place, and rechecking, folder-by-folder and file-by-file), I encountered the very uninformative User Manager page as depicted in the attached JPEG file.
What you see there is the version, with name redaction, resulting (in addition to my own information as administrator) from going through the self-registration process for two users. Until I did that, I had no way of knowing how to use the form. It was after unsuccessful trial and error that I did the self-registration.
I've also attached the source code (dokuwiki.php) corresponding to the screen depicted in the JPEG file. To protect their privacy, I've redacted (using x's) the names of the two initial users.