Reading the suffix letter on a USB adapter's part number
A short question asked how two near-identical USB 802.11n chip numbers differ. The single reply said the trailing letter marked a lower-cost variant of the same chip.
Nothing more was said about what differs between the variants, so the summary stops there.
Takeaway. A suffix letter can mark a cost or feature variant of one chip family, but its meaning differs between makers. Check the data sheet for the exact part.