How to use the FRM BL (Firm Bundling) parameter to make Periodicals Firm Bundles correctly in MailStream Plus

A mailing consisted of two different periodicals going to each address.  But the mailer said that in the Mail.dat files, it only reflected one periodical.  The user wanted to know how to tell MailStream Plus (MSP) that there were two periodicals in each 'firm bundle'?

The problem cause was that the mailer was making the 'firm bundles' prior to MSP.  
They were combining the pieces so that the job only had one P ATTR parameter that contained the combined weight, thickness, etc.  And the input Name-Address file only had one record going to each address.  Therefore, as far as MSP knew, there was only one periodical going to each address. 

What needs to be done in this type of situation is to have MSP do the Firm Bundling.  
This is done (using the mailing above as an example) by having two input Name-Address records for each address.  And have two P ATTRs, one for each of the Periodicals with just that Periodical's weight, thickness, etc.  And have one input record for each address use one P ATTR, and the other input record for the same address use the other P ATTR.
Then use the FRM BL parameter to tell MSP to make the Firm Bundles.

And then in the job, PA INF parameters are used with the periodical-related subkeywords to tell MSP the information for each of the Periodicals involved, such as the Publication Title for each, the publication number for each, etc.

MSP will then be able to generate the Mail.dat files correctly to reflect that it is a firm bundle mailing, and with the correct information for each of the Periodicals.
UPDATED:  August 7, 2017