Why are proprietary packages in main?

[Avinash Sonawane]

Hello!

https://help.ubuntu.com/community/Repositories/Ubuntu says "Main -
Canonical-supported free and open-source software." but non-free
packages like amd64-microcode and intel-microcode are in main.

Why is that? Has the meaning of "main" changed? (From that same ubuntu
help page it seems that these blob packages should be in "restricted".)

Thanks!

Regards,
Avinash Sonawane (rootKea)
PICT Pune
https://rootkea.wordpress.com