How to tell why some Periodicals get a DDU container charge, when the mail is being entered at an SCF in MailStream Plus

In a Periodical mailing that is being entered at an SCF, and the job is not asking for DDU discounts, some Containers charges get the E41 “5-Digit/Carrier Route Sack/Tray - DDU” rate in the "Sack and Tray Prices" section of the 3541 Postage Statement.

The reason for this is that Trays/Sacks will get the DDU Container rate if the DDU and SCF are co-located at the same facility.  MailStream Plus (MSP) knows when this is the case because the SCF and the co-located DDU's ZIP Codes will have the same Locale Key in the USPS FAST files.  Having the same Locale Key indicates they are at the same location.

So for determining container charges, it doesn't matter whether the pieces are getting or asking for a DDU rate or not.  If the SCF entry facility is with a DDU, the Container charge is based on that for eligible sacks going to that DDU's ZIP Codes.

FYI- It was found that about 10% of the SCFs also have a DDU(s) co-located with them.
UPDATED:  August 7, 2017