Chameleon makes it easy to deal with special types of messages, using the Special Messages tab. Each option is described in the screenshot below:
In order to be routed to default message, the incoming message
has to be successfully parsed. One useful function of this message is to
auto-acknowledge any unrecognized messages
and to log the unknown messages for troubleshooting later.
Do not define any mandatory segments in the default message besides
message header since you will not know anything about the structure of unrecognized
messages. In order to be routed to the default message, incoming messages must be successfully parsed.