* doc/mach.texi (Message Format): Document msgh_protected_payload.
---
doc/mach.texi | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/doc/mach.texi b/doc/mach.texi
index 67c5fe9..251c290 100644
--- a/doc/mach.texi
+++ b/doc/mach.texi
@@ -1330,6 +1330,15 @@ which is conventionally used as a reply port by the
recipient of the
message. The field must carry a send right, a send-once right,
@code{MACH_PORT_NULL}, or @code{MACH_PORT_DEAD}.
+@item mach_port_t msgh_protected_payload
+The @code{msgh_protected_payload} field carries a payload that is set
+by the kernel during message delivery. The payload is an opaque
+identifier that can be used by the receiver to lookup the associated
+data structure.
+
+It is only valid in received messages. See @ref{Message Receive} for
+further information.
+
@item mach_port_seqno_t msgh_seqno
The @code{msgh_seqno} field provides a sequence number for the message.
It is only valid in received messages; its value in sent messages is
--
1.8.5.2
