Wii Number

The Wii Number is the 16-digit (and 64 bit) friend code of your Wii, which can be registered with other Wiis to exchange mail via WiiConnect24 (and now WiiLink).

It's made up of a few variables that identify your Wii:

• Hollywood ID
  • The unique id of the Hollywood chip in the Wii
  • A 32 bit unsigned int
• Counter (mod 32)
  • Increments every time you format your Wii, can range from 0-31, and back wraps around to 0 after it surpasses 31
• Hardware Model
• A 3 bit unsigned int, however, always lower than 4 as only 3 models where released to begin with
  • For Commercial Hardware:
    • RVL-001 = 1 (Original Model)
    • RVL-101 = 2 (Family Edition)
    • RVL-201 = 3 (Wii mini)
  • For Developer Hardware:
    • RVT-001 = 1^[check]
    • Unknown if there are more
• Area Code:
  • A 3 bit unsigned int, always lower than 4 as there was never more than 4 regions supported.
  • The values correlate as follows
    • Japan ("J") = 0,
    • USA ("U") = 1,
    • Europe ("E") = 2,
    • Korea ("K") = 3
• CRC Checksum
  • Presumed to be a CRC10 checksum as it is contained within a 10 bit unsigned int^[check]

These variables are then scrambled using a ton of complicated bitwise operations.

RiiConnect24 has source code to encode and decode a Wii Number. It has been ported to C, Golang, and Python.

Refrences

↑ 1. https://github.com/GaryOderNichts/vWii-Decaffeinator/blob/master/src/main.h
↑ 2. https://github.com/GaryOderNichts/vWii-Decaffeinator/blob/master/src/main.h
↑ 3. https://github.com/GaryOderNichts/vWii-Decaffeinator/blob/master/src/main.h
↑ 4. Guess and check with a friend code decoder and a Korean Wii