[drupal-support] drupal.org template feature

[Abalieno]

I've noticed that the official site uses two different settings for the 
layout by default.

On the normal nodes on the homepage the comments are shown by default in a 
threaded mode, while on the forum they are shown as a flat list.

Is this possible in a normal version of the engine or it's a specific hack 
just for drupal.org?
All I know is that I can set a general preference but I cannot set the 
homepage in a way and the forum in another.

-HRose / Abalieno