How to tell if MailStream Plus handles Franking

No, MailStream Plus does not have any specific parameters to handle USPS Franking or Franked mail.

Per this USPS article –
This is handled by specifics Permits.  So you can use the xx INF with the subkeyword PMTPM# to assign that permit number.
There is no other specific parameter to use.
** Note this USPS article is current as of Dec. 2015.
UPDATED:  August 11, 2017