VERIFIED SOLUTION i

MailStream Plus 'P ATTR' and 'ENT PT' codes must match to mail piece records for them to be used.

When a job has multiple P ATTR parameters you tell MailStream Plus (MSP) the location and length of the indentifier code in the records.  That is used to match to the Indentifier Code in positions 14-22 of the P ATTR parameter.  If no P ATTR is found that matches the code in the record(s), then the default P ATTR will be used, or if there is no default then the job will abend with a "1050: Piece-ID not found ..." error

Similarly, when a job has multiple ENT PT parameters, the E CODE parameter tells MSP where to look in the records for the information to match each record to one of the ENT PT parameters.  If no ENT PT is found that matches the record, then the default ENT PT will be used, or if there is no default then the job will abend with a "1055: Entry point E not found and no default" error.
UPDATED:  April 18, 2017