Update admin-guide/configuration/desktop/xrdp-mod-admin-guide.md

admin-guide/configuration/desktop/xrdp-mod-admin-guide.md

@@ -1,11 +1,30 @@
 # Configuration for the Remote Desktop Access
 
-The xrdp modification allowing for remote desktop access to existing physical display sessions (see [xrdp-mod](https://gitea.psi.ch/muelle_v/local_desktop_session_xrdp)) can be modified in the in the `xrdp-config`file.
+The xrdp modification allowing for remote desktop access to existing physical display sessions (see [xrdp-mod](https://gitea.psi.ch/muelle_v/local_desktop_session_xrdp)) can be configured by creating a file `xrdp-config` in `/etc/xrdp-mod/xrdp-config`:
+
+```bash
+# Configuration for xrdp-mod behavior
+
+# Policy for connecting to current local desktop session
+#    VirtualOnly	- Access to local desktop session is not allowed
+#    OwnDisplayOnly	- Users can only access local display session if they are the owner
+#    SharedDisplay	- All users are allowed to connect to current display session
+AccessPolicy=SharedDisplay
+
+# Allow for virtual sessions as fallback (0 for No, 1 for Yes) 
+VirtualSessions=1
+
+# Log levels; ERROR, INFO, DEBUG
+LOG_LEVEL=DEBUG
+```
 
 The variables `AccessPolicy` and `VirtualSessions` can be set to the options as described in the `xrdp-config` file.
 
+If the file is not specified, the xrdp modification will default to `AccessPolicy=OwnDisplayOnly`, `VirtualSessions=1`, and `LOG_LEVEL=DEBUG`.
 
 # Restarting xrdp and its modifications
 
 xrdp can be restarted and the xrdp modifications reset with the script `restart-xrdp`. In order to restart the process for single users only, the script `restart-for-user` can be called with the user id as argument.
-
+```bash
+/path/to/xrdp-mod/restart-for-user <UID>
+```