National Population Gamer Registration Code

A National Population Gamer Registration Code (NPGRC; Spanish: Código de registro de jugador de la población nacional or CRJPN) is a unique numeric code that identifies gamers, usually, the ones using Nintendo 3DS or Wii U. This system is run by the Madrid Cooperation for Gameplays and Gameplayers (Spanish: Cooperación Madrid para jugadas y jugadores), based in Madrid, Spain.

The National Population Gamer Registration Code is required for every Nintendo 3DS or Wii U gamer so that the gamer using Nintendo 3DS or Wii U can buy games or order Nintendo eShop gift cards from Madrid Cooperation for Gameplays and Gameplayers (only in Spain). The National Population Gamer Registration Code must be also used to register some sites such as http://www.nintendo-on.com.

A National Population Gamer Registration Code just identifies only one gamer, not two or more gamers (since it is a unique identifier).

Structure
The National Population Gamer Registration Code consists of three groups of three digits separated by spaces plus checksum (in the format xxx xxx xxx.x, final x is 0-9, K).

Validation of National Population Gamer Registration Code
Validation of National Population Gamer Registration Code is as follows:
 * 1) Remove spaces and the full stop
 * 2) Multiply from left to right, first 9 digits with the following factors: 10, 2, 9, 8, 7, 6, 5, 4, 3
 * 3) The products are obtained and added up
 * 4) Do the division of the sum by 11 and find the remainder.
 * 5) Determine the checksum:
 * 6) * If there is no remainder, the checksum is 0 (zero)
 * 7) * If the remainder is 10, the checksum is the letter K
 * 8) * If the remainder is between 1 and 9, the checksum is the remainder
 * 9) If the original checksum is the same as the calculated checksum, this means that the National Population Gamer Registration Code is valid.

Example of checksum calculation: 956 129 370.9
Checksum calculation for NPGRC 956 129 370.9: 9 5  6  1  2  9  3  7  0  9 10 2  9  8  7  6  5  4  3     <- Weighing factor 9 * 10 = 90 5 * 2 = 10 6 * 9  = 54 1 * 8  = 8 2 * 7  = 14 9 * 6  = 54 3 * 5  = 15 7 * 4  = 28 0 * 3  = 0   Sum  = 273 024 9) 273    0     27    22      53     44       9 273 divided by 11 equals 24 with a remainder of 9. Valid NPGRC number (the last digit is indeed 9).