apt-mark — Utility to change the status of installed packages. More information: <https://manned.org/apt-mark>.

Mark a package as automatically installed

sudo apt-mark auto {{package}}

Hold a package at its current version and prevent updates to it

sudo apt-mark hold {{package}}

Allow a package to be updated again

sudo apt-mark unhold {{package}}

Show manually installed packages

apt-mark showmanual

Show held packages that aren't being updated

apt-mark showhold