| 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[1]) is a simple coordinate system on a grid in which each cell is identified by a combination of a letter and a number.[2]
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.[3]
Some kinds of geocode also use letters and numbers, typically several of each in order to specify many more locations over much larger regions.