~/.cache
28. 10. 2019freedesktop.org was formerly known as the X Desktop Group, and the acronym “XDG”, remains common in their work.
https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html
If $XDG_CACHE_HOME is either not set or empty, a default equal to $HOME/.cache should be used.
https://wiki.archlinux.org/index.php/XDG_Base_Directory#Specification
cd .cache
duh2 | tail
53M ./jhbuild
91M ./supertuxkart
140M ./godot
142M ./winetricks
262M ./RawTherapee
403M ./thumbnails
526M ./mozilla
823M ./google-chrome
2.6G .
2.6G total
Everything in enviroment considering XDG (Debian Buster Openbox)
printenv | grep XDG
XDG_SEAT=seat0
XDG_SESSION_TYPE=x11
XDG_SEAT_PATH=/org/freedesktop/DisplayManager/Seat0
XDG_SESSION_CLASS=user
XDG_SESSION_ID=1
XDG_SESSION_PATH=/org/freedesktop/DisplayManager/Session0
XDG_RUNTIME_DIR=/run/user/1000
XDG_SESSION_DESKTOP=openbox
XDG_GREETER_DATA_DIR=/var/lib/lightdm/data/b
XDG_VTNR=7
XDG_DATA_DIRS=/home/b/.local/share ...