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Determining how MailStream Plus generates what the tray or sack label's content lines should have

MailStream Plus™, all versions, all platforms
The USPS Domestic Mail Manual (DMM) gives all the rules about how to presort mailing into bundles, trays, sacks, etc.  And it also tells how to label the bundles or Trays or Sacks. 

The below DMM references are as of April 2018.  Currently  the DMM can be found here-
https://pe.usps.com/text/dmm300/dmm300_landing.htm

For example if the mailing is First-Class letters, DMM 235 gives the Mail Preparation instructions.

For First-Class Automation letters, it would be per 235 6.0, and 6.6 tells what Tray Line 2 (the 'Content Line') should say, depending on the presort level of the tray.  They all have 'BC' required as shown in the contents lines, indicating fully Automation-compatible.

For First-Class Non-Auto letters, they may be:
1) Physically machinable, but just do not have a full ZIP/ZIP+4/Delivery Point Code on them.  Per DMM 235 5.2.2 Tray line 2 will have 'MACH' included in it, as shown, depending on the presort level of the tray.
--or-- 
2) They may physically not be able to be processed on the USPS machines.  Per DMM 235 5.3.2 Line 2 will have 'MANUAL' in the line, as shown, depending on the presort level of the tray.
UPDATED:  May 16, 2018