vrms (Virtual Richard M. Stallman) is a program that analyzes the set of currently-installed packages on a Debian-based system, and reports all of the packages from the non-free tree which are currently installed. Software gets placed in the non-free tree when it is agreed not to be too problematic for Debian to distribute but does not meet the Debian Free Software Guidelines and therefore cannot be included in their official distribution. For each program from "non-free" installed, vrms displays an explanation of why it is non-free, if one is available.
Have you installed VMRS?
https://en.wikipedia.org/wiki/Vrms
vrms (Virtual Richard M. Stallman) is a program that analyzes the set of currently-installed packages on a Debian-based system, and reports all of the packages from the non-free tree which are currently installed. Software gets placed in the non-free tree when it is agreed not to be too problematic for Debian to distribute but does not meet the Debian Free Software Guidelines and therefore cannot be included in their official distribution. For each program from "non-free" installed, vrms displays an explanation of why it is non-free, if one is available.