Is the CPP discount officially defined anywhere?

[synplet]

I've googled to no avail.

Can someone point me to the latest, definitive specification on exactly what the commercial plus discount is on USPS postage?

I specifically am trying to found out the discount for first class international packages.  According to stamps.com, it's "up to 5%" for first-class international.  Can it be that small?

[nobody*s_perfect]

There seems to currently be no difference between the USPS published Commercial Base and Commercial Plus rates for First Class Package International service, although the official USPS rates publication (Notice 123) maintains separate tables for the two sets of prices:

https://pe.usps.com/text/dmm300/Notice123.htm#_c391

eBay claims that they have negotiated some postage rates that are lower than the published USPS rates; I haven't seen any in the domestic charts and I don't ship internationally, but perhaps in some cases the eBay rates for Top Rated Sellers are lower than the USPS published rates.

Of course it's also possible that stamps.com has negotiated rates that are different from the published USPS rates and/or from the  rates that eBay charges.

[berserkerplanet]

>>but perhaps in some cases the eBay rates for Top Rated
>>Sellers are lower than the USPS published rates.

I don't ship internationally (any more) either. A seller who does have an international order laying around in Sold Listings could do a "Print another label", play with the numbers on the eBay label page for various services (where any TRS/Comm+ discounts will show), and see if those rates are any better than published Comm/Comm+ rates.