Indeed, at "allow-all-access" on the xdm man page, one could mention
parts of this from the nodm man page,
However, there are cases where automatic login is needed: for example in an embedded system such as a mobile
phone, or in a kiosk setup, or in a control panel for industrial machinery. For those cases, nodm is simple to
setup, lightweight, and it should do exactly the right thing.
and add nodm(8) to SEE ALSO,