What is the default ports tree in FreeBSD 12.1? Easiest way to change it?

Starting with a fresh install of FreeBSD-12.1-RELEASE , when I run # portsnap fetch # portsnap extract does it extract the release branch, quarterly branch, HEAD or some other branch? Is there a config setting somewhere to change this or should I use subversion to track another ports tree? I'm fine using subversion, so I don't need a run down on that. Just wondering what the default is and if there's a simpler config to tweak and avoid it. Also, I understand that pkg uses the quarterly branch by default, but I'm not finding similar information on about ports.