apt/debian/apt.conf.autoremove

APT
{
  NeverAutoRemove
  {
	"^firmware-linux.*";
	"^linux-firmware$";
  };

  VersionedKernelPackages
  {
	# linux kernels
	"linux-image";
	"linux-headers";
	"linux-image-extra";
	"linux-signed-image";
	# kfreebsd kernels
	"kfreebsd-image";
	"kfreebsd-headers";
	# hurd kernels
	"gnumach-image";
	# (out-of-tree) modules
	".*-modules";
	".*-kernel";
	"linux-backports-modules-.*";
  };

  Never-MarkAuto-Sections
  {
	"metapackages";
	"restricted/metapackages";
	"universe/metapackages";
	"multiverse/metapackages";
	"oldlibs";
	"restricted/oldlibs";
	"universe/oldlibs";
	"multiverse/oldlibs";
  };
};