Index: lib/libc/sys/send.2
===================================================================
--- lib/libc/sys/send.2
+++ lib/libc/sys/send.2
@@ -75,6 +75,11 @@
 and
 .Fn sendmmsg
 may be used at any time.
+.Fn sendto
+on connection-oriented sockets should be done on sockets in connected state,
+or the caller should be prepared to handle ENOTCONN and do a
+.Fn connect
+on the socket to recover.
 .Pp
 The address of the target is given by
 .Fa to
@@ -195,6 +200,12 @@
 The destination address is a broadcast address, and
 .Dv SO_BROADCAST
 has not been set on the socket.
+.It Bq Er ENOTCONN
+The socket is associated with a connection-oriented protocol
+that does not support implied connect (currently
+.Xr tcp 4
+is the only protocol with support) and has not been connected (see
+.Xr connect 2 ) .
 .It Bq Er ENOTSOCK
 The argument
 .Fa s