What is the purpose of each of the eight MailStream Plus Postal Reference files

Produce Affected:  MailStream Plus™
Product Feature: USPS Postal Reference Files
Operating System: Not stated
Here are the list of the eight MailStream Plus™ (MSP) Postal Reference files(PRF) and the purpose of each :
>   MSRFDC DD   (PRFDLVCT)   Delivery Counts - contains the counts for deliveries for each zip/CRRT
>   MSRFDI DD     (PRFDSTNM)  Destination Information - contains the USPS Labeling list information
>   MSRFMC DD   (PRFMLCTL )  Mailing Control - contains the Drop Ship File Contain USPS Faculty information
>   MSRFMP DD   (PRFRTMAP)  Routing Map - contains the routing/destination information for each 3-digit ZIP code prefix.
>   MSRFPS DD    (PRFPSTMT)  Statements - contains the statements, Rates and other Presort control Data
>   MSRFSQ DD   (PRFSQREF)   Sequencing - contains the NDC Sequencing information
>   MSRFZD DD   (PRFZIPDR )    ZIP Code Directory - contains the USPS zip codes
>   MSRFZM DD  (PRFZONES)   Zone Map -  contains the Zone information

The MSP PRF files are generated monthly.  
UPDATED:  March 11, 2019