A was a digital voucher. When you bought a game, Nintendo’s servers attached a ticket to your console. That ticket proved you owned the game and allowed you to re-download it for free if your SD card failed.
Disclaimer: This post is for educational and historical purposes. Always respect copyright laws and Nintendo’s terms of service. Free Wii Download Ticket Codes
If you really want to play Dr. Mario or Bomberman Blast on original hardware again, your best bet is learning how to softmod your Wii. It’s legal, well-documented, and gives you full control over your console—no fake ticket codes required. A was a digital voucher