If checked, the global configuration matrix will not be inherited.
This allows you to configure a job that has a more strict access control list than the rest of the global permission set.
WARNING: because the parent ACL will not be inherited, it is possible to revoke your own configuration access accidentally.
If you enable this setting, please also remember to grant yourself or your group configuration access so that you do not lock yourself out of the job.
Otherwise the only ways to get back in will be to disable project-based security in global configuration, or manually edit the permissions list in the project's XML configuration.