So prior to yesterday, my new and clean $HOME had not seen any X session at all. No freedesktop defined XDG base directories.
Then I logged in and…
…wait, what’s that? XDG Base Directories?
OK, so, we all know and love (hate?) our ~/Desktop, ~/Downloads, ~/Templates, ~/Public, ~/Documents, ~/Music, ~/Pictures, ~/Videos directories, right? Well, they’re defined as a freedesktop standard (see here: http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html ), and are configured locally at: ~/.config/user-dirs.dirs
So prior to logging in to X, I had three of those eight already, since they had actual content from my backups – ie, were worth restoring already. They were: ~/Desktop, ~/Public, and ~/Videos
After logging in, I naturally gained the other 5.
But what else got pushed into $HOME? Luckily for posterity, I saved a file list both before and after. So, for no more than a simple login to X, and run a few apps (discounting internal configuration tools, I think I’ve really only run gnome-terminal, firefox, thunderbird, chromium and libreoffice so far), I have these files/directories extra…
So, there is a list I only expect to grow (but not to track) over time, and it’s entirely possible I’ve missed some (I’ve certainly skipped a few I know I added manually (.fonts, .fontconfig) since I don’t know if they’d have been automatically added or not.
Anyway, the upshot of all this? Hello cruft!