about dnf installonlypks

[Sérgio Basto]

Hi,
after searching a lot still can't find how installonlypks package list
is generated 

I found these 2 references : 
https://dnf.readthedocs.io/en/latest/command_ref.html
https://docs.fedoraproject.org/en-US/Fedora/24/html/System_Administrators...

dnf repoquery --installonly
    Limit the resulting set to installed installonly packages.

I see the list of installonlypkgs , but where in Centos Stream 9, I get
his list of installonlypkgs and how I can modify it i.e. what package
set or unset packages on this list of installonly pakages ? 

Thank you,
-- 
Sérgio M. B.