/etc/selinux/default/contexts/customizable_types is in selinux-policy-default 2:2.20161023.1-9.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 | mount_loopback_t
public_content_rw_t
public_content_t
swapfile_t
|