Could also say "Use the err(3) and warn(3) family of functions." That's
what the err(3) man page intro refers to it as.
Index: share/man/man9/style.9
===================================================================
RCS file: /cvs/src/share/man/man9/style.9,v
retrieving revision 1.59
diff -u -p -r1.59 style.9
--- share/man/man9/style.9 23 Jan 2015 13:02:49 -0000 1.59
+++ share/man/man9/style.9 22 Sep 2015 02:36:46 -0000
@@ -522,10 +522,10 @@ Routines returning
should not have their return values cast to any pointer type.
.Pp
Use
-.Xr err 3
-or
+.Xr err 3 ,
.Xr warn 3 ,
-don't roll your own!
+or one of their variants.
+Don't roll your own!
.Bd -literal -offset indent
if ((four = malloc(sizeof(struct foo))) == NULL)
err(1, NULL);
