on commit {
    if (pick-first-value(var-os-fingerprint, "NULL") != "NULL" and
	    var-os-fingerprint != "unknown") {
	log(info,
	    concat(
		"fingerprint host ",
		binary-to-ascii(16, 8, ":", substring(hardware, 1, 6)),
		" (",
		binary-to-ascii(10, 8, ".", leased-address),
		") has parameter list ",
		binary-to-ascii(16, 8, ":", option dhcp-parameter-request-list),
		" and appears to be ",
		var-os-fingerprint
	    )
	);
    } else {
	log(info,
	    concat(
		"fingerprint host ",
		binary-to-ascii(16, 8, ":", substring(hardware, 1, 6)),
		" (",
		binary-to-ascii(10, 8, ".", leased-address),
		") has parameter list ",
		binary-to-ascii(16, 8, ":", option dhcp-parameter-request-list),
		" and is unidentified (NULL)"
	    )
	);
    }
}