https://bugzilla.redhat.com/show_bug.cgi?id=2165381
--- Comment #7 from Benson Muite benson_muite@emailplus.org --- Guidelines are not clear on this. Full patent search seems difficult. Given their age, expect not or if they had they are expired, but for compression typically good to check. Raised an issue: https://github.com/temisu/ancient/issues/41