From the USPS Domestic Mail Manual, section 170, subsection 4.1(i):
"Computer-readable media containing prerecorded information and guides or
scripts prepared solely for use with such media."
Sellam
On Tue, Oct 11, 2022, 8:23 AM Fred Cisin via cctalk <cctalk(a)classiccmp.org>
wrote:
  On Tue, 11 Oct 2022, Bill Gunshannon via cctalk wrote:
  On the other side of the coin...  I once tried to
sell a couple
 Chilton's car manuals.  The shipping price I quoted was the cost
 of a "If it fits, it ships" USPS envelope.  eBay refused to let
 me do it claiming the shipping charges were too high.  I haven't
 tried selling anything on eBay since.  (and I have a lot of stuff
 that just screams to be sold there!!)
 
 "Media mail" is the only practical option for those.
 And, blank, or user-written diskettes don't qualify; according to the
 post-office, only commercially written disks.