The standard CDE configuration files live in /usr/dt/config. You're not supposed to edit them there, but copy the files you want to modify to /etc/dt/config and edit them there. The /etc/dt directory does not exist, you must create it.
Customizing dtgreet, the login widget, is done through /etc/dt/config/C/Xresources; near the end you'll find the following:
!! To disable options in dtgreet window, uncomment the appropriate !! line below.!Dtlogin*options_noWindows*sensitive: False !Dtlogin*remote_host_menu*sensitive: False !Dtlogin*options_languages*sensitive: False !Dtlogin*session_menus*sensitive: False !Dtlogin*options_restartServer*sensitive: False
!! To disable options under remote login option menu, uncomment the !! appropriate line below.
!Dtlogin*remote_login_host*sensitive: False !Dtlogin*choose_login_host*sensitive: False
By removing the ! in front of the !Dtlogin you can disable the following menu items, respectively:
1) Command Line Login
2) Remote Login
3) Language choice
4) Session choice
5) Reset Login Screen
6) Under the "Remote Login" menu, "Enter Hostname ..."
7) Under the "Remote Login" menu, "Choose Host From List ..."
Two undocumented options, "options_failsafe" and "options_last_dt", can be used to disable the Failsafe and Last Session choices, though the default will continue to be "Last Session".
By commenting out the following lines by prepending them with a exclamation mark (!), you can disable the CDE environment login (and force users to use the other choices)
Dtlogin*altDts: 1Dtlogin*altDtName1: Common Desktop Environment (CDE) Dtlogin*altDtKey1: /usr/dt/bin/dtwm Dtlogin*altDtStart1: /usr/dt/bin/Xsession Dtlogin*altDtLogo1: Dtlogo
The OpenWindows Desktop can be disable by creating an empty "/etc/dt/config/C/Xresources.d/Xresources.ow" file. Other desktops can be added by creating files like Xresources.ow in the Xresources.d directory.