xdr_authsys_parms(3) on FreeBSD
The text f27147222b95, as FreeBSD 5.5-RELEASE, FreeBSD 5.4-RELEASE, FreeBSD 5.3-RELEASE, FreeBSD 5.2.1-RELEASE, FreeBSD 5.2-RELEASE, FreeBSD 5.1-RELEASE, FreeBSD 5.0-RELEASE shipped it.
XDR library routines for remote procedure calls