How to know the data that EXITOP passes to the user's routine from MailStream Plus

MailStream Plus- all platforms, all versions
EXITOP Routine Processing
The exit routine receives the following parameter list using standard linkage.

• A single byte indicating the function performed:
 O - Open the file.
 W - Write the record.
 C - Close the file.

• A two-byte field containing one of the following File Activator characters describing the file:
Activator Code Work File Description
CF MSWKCF Control file for qualification sort
CM MSWKCM Statistics step communication file
DT MSWKDT Detail statistics file
MS MSWKMS Mail sequence statistics file
NR MSWKNRC Name record report file
ON MSNAON Posting name/address output
OR MSSTOR Rejected records
OS MSST0N Statistics name/address output
SF MSNDSSF Shipping services file
SS MSWKSS Statistics work file

• The record to write to the file (this parameter is not referenced for OPEN and CLOSE operations)

• The 80-byte EXITOP parameter
UPDATED:  September 6, 2017