The exception are styled pages in the userspace - accessed by username.dreamwidth.org/ with /read /calendar and entry pages being the big ones.

You will find the info on what is being displayed in those in cgi-bin/LJ/S2/ , and hoe they are displayed in bin/upgrading/s2layers/core2.s2 . There is also cgi-bin/LJ/s2.pm , which you might want to look at.

It's Complicated :)