.Sh SYNOPSIS
.Fd #include <unistd.h>
.Ft pid_t
-.Fn vfork void
+.Fo vfork
+.Fa void
+.Fc
.Sh DESCRIPTION
.Fn Vfork
can be used to create new processes without fully copying the address
.Xr exit
since buffered data would then be flushed twice.)
.Sh SEE ALSO
-.Xr fork 2 ,
.Xr execve 2 ,
+.Xr fork 2 ,
.Xr sigaction 2 ,
-.Xr wait 2 ,
-.Sh DIAGNOSTICS
-Same as for
-.Xr fork .
+.Xr wait 2
+.Sh ERRORS
+The
+.Fn vfork
+system call will fail for any of the reasons described
+in the
+.Xr fork
+man page.
+In addition, it will fail if:
+.Bl -tag -width Er
+.\" ===========
+.It Bq Er EINVAL
+A system call other than
+.Xr _exit()
+or
+.Xr execve()
+(or libc functions that make no system calls other than those)
+is called following calling a
+.Fn vfork
+call.
+.El
.Sh BUGS
This system call will be eliminated when proper system sharing
mechanisms are implemented.