/usr/lib/sddm/sddm.conf.d
System configuration directory
Sddm display manager greeter
sddm-greeter [OPTIONS ...]
sddm is a display and login manager based on Qt technologies.
Using QtQuick and QML, designers are given the ability to easily create pleasant, modern looking interfaces for sddm.
sddm-greeter is an auxiliary process that displays the greeter, a graphical user interface to perform the authentication and select the session to run.
It is launched by the sddm daemon, end users are not meant to run it.
--theme PATH
Specify theme full path.
--socket NAME
Specify the socket used to communicate with sddm daemon.
--test-mode
Start greeter in test mode.
--help, -h
Show help message and exit.
/usr/lib/sddm/sddm.conf.d
System configuration directory
/etc/sddm.conf.d
Local configuration directory
/etc/sddm.conf
Local configuration file for compatibility
/usr/share/sddm/themes
Where sddm looks for themes
6 releases since Debian 9 (Stretch); the text changed 5 times.