a b c d e f 1 a1 b1 c1 d1 e1 f1 2 a2 b2 c2 d2 e2 f2 3 a3 b3 c3 d3 e3 f3 4 a4 b4 c4 d4 e4 f4 5 a5 b5 c5 d5 e5 f5 6 a6 b6 c6 d6 e6 f6
An alphanumeric grid (also known as atlas grid) is a simple coordinate system on a grid in which each cell is identified by a combination of a letter and a number. Retrieved 2010-03-22.
An advantage over numeric coordinates such as easting and northing, which use two numbers instead of a number and a letter to refer to a grid cell, is that there can be no confusion over which coordinate refers to which direction. As an easy example, one could think about battleship; simply match the number at the top to the number on the bottom, then follow the two lines until they meet in a spot.
Algebraic chess notation uses an alphanumeric grid to refer to the squares of a chessboard.http://www.fide.com/fide/handbook?id=125&view=article Appendices in World Chess Federation Handbook: see part C.7 of section C. Algebraic notation. Retrieved 2010-03-22.
Some kinds of geocode also use letters and numbers, typically several of each in order to specify many more locations over much larger regions.
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