It looks like copyright for sys/kern/sysv_ipc.c was assigned to NetBSD in rev 1.13 in 1998:
http://cvsweb.netbsd.org/bsdweb.cgi/src/sys/kern/sysv_ipc.c.diff?r1=1.12&r2=1.13&only_with_tag=MAIN&f=h NetBSD then dropped clauses 3 & 4 in rev 1.21 in 2008: http://cvsweb.netbsd.org/bsdweb.cgi/src/sys/kern/sysv_ipc.c.diff?r1=1.20&r2=1.21&only_with_tag=MAIN&f=h Not sure if there's any interest in updating in OpenBSD...