Reference ffs32(3). Also note POSIX compliance and the movement of the

header from <string.h> to <strings.h>.

lib/libc/string/ffs.3

@@ -28,9 +28,9 @@
 .\" SUCH DAMAGE.
 .\"
 .\"     from: @(#)ffs.3	8.2 (Berkeley) 4/19/94
-.\"	$NetBSD: ffs.3,v 1.11 2009/07/21 13:22:15 wiz Exp $
+.\"	$NetBSD: ffs.3,v 1.12 2010/04/28 07:44:04 jruoho Exp $
 .\"
-.Dd July 21, 2009
+.Dd April 28, 2010
 .Dt FFS 3
 .Os
 .Sh NAME
@@ -53,9 +53,22 @@ bit.
 A return value of 0 means that the argument was zero.
 .Sh SEE ALSO
 .Xr bitstring 3 ,
+.Xr ffs32 3 ,
 .Xr popcount 3
+.Sh STANDARDS
+The
+.Fn ffs
+function conforms to
+.St -p1003.1-2001 .
 .Sh HISTORY
 The
 .Fn ffs
 function appeared in
 .Bx 4.3 .
+The prototype for it existed previously in the
+.In string.h header
+before it was moved to
+.In strings.h
+for
+.Tn POSIX
+compliance.