P ATTR position 66 and Periodical Flats using MailStream Plus (and DMM 207.26)

In 2014, the USPS renumbered the DMM.  For Periodical Flats mailings, what are the new DMM references and how they equate back to the P ATTR values on Position 66?
Y - Mailpieces with this attribute are automation compatible, or are machinable pieces.
This is DMM 201.6.0 - Physical Standards for Automation Flats 
F - FSM1000 mailpiece (for Periodicals only).  – This is the old naming we still have on this parameter
This is DMM 207.26   - 26.0 Physical Criteria for Nonmachinable Flat-Size Periodicals
S-  Non-machinable Periodicals flats (for Periodicals only).
**Note above is current as of June 2015.

FYI- Where does it say that using an F and using the 207.26 Physical Standards is allowed for barcoded automation (i.e. machinable) flats?  
DMM 207 25 is for "Preparing Flat-Size Barcoded (Automation) Periodicals"
25.1 Basic Standards
25.1.1 General
"Each piece must meet the physical standards in 201.6.0 or in 26.0."

UPDATED:  April 12, 2017