As part of transaction 'messid' on path 'path', the user wishes to send the message AS A REPLY to a previously received message from the other end of the path. The user can ONLY reply with a MESSYS__DE_INIT message (something has gone wrong) or with a normal MESSY__MESSAGE message. Any other value of message_function will result in status MESSYS__MSGFUNC being returned.
A MESSYS__MESSAGE message may be a GSOC_END, terminating a transaction or one of the various other types, MESSYS__INFORM, MESSYS__PARAMREQ etc.
AMS The Unix ADAM Message System