I've a few trading cards for some arcade games:
Sega Love and Berry
Sega Mushiking (Japanese and European cards).
Bandai Dragon Ball Heroes
Bandai Carddass (Yokai, DBZ, Majin Bone)
Square Enix Lord Of Vermillon
Bandai Gundam Try Age
Sega Sengoku Taisen
Also some Pokemon Tretta tokens...
Some of them uses barcodes, the Pokemon Tretta tokens contain dot codes you see under UV light, some other cards have printed QR codes, probably other are RFID or similar...
Is someone archiving scans or "dumps" of these cards? There are thousands of them, it will be very hard to have complete sets, but maybe is a good idea to start "preserving" them...