:0 Local local@console /usr/openwin/bin/Xsun :0
:0 means that the Xserver display is <localhost:0>.
Replace local with foreign if you want to attach to a running X11 server.
/usr/openwin/bin/Xsun is the path to the X11 server.
Refer to the dtlogin(1) man page for more information about this file. You can also review the explanatory comments in the file itself.