The QR code is not the instruction
A QR code carries an address string and nothing else. It does not carry the network, and a scanning wallet will not warn your client that they are about to send USDT over the wrong chain to an address that happens to be valid on both.
So the label matters as much as the code. Print the asset and the network together — 'USDT on TRON (TRC20)' — next to the image, and print the address in text as well, because some clients copy and some scan and you do not get to choose which.
