Conventional Irish grid references are 1 m, 10 m, 100 m, 1 km, 10 km or 100 km in precision.
In some scenarios a precision of 2000 m is useful. A tetrad is a block of 2 x 2 adjacent 1 km squares. There are 25 tetrads in a 10 km square. A tetrad grid reference can be given by a 10 km grid reference followed by a single letter (the letter O is skipped).
Conventional Irish grid references are 1 m, 10 m, 100 m, 1 km, 10 km or 100 km in precision.
In some scenarios a precision of 2000 m is useful. A tetrad is a block of 2 x 2 adjacent 1 km squares. There are 25 tetrads in a 10 km square. A tetrad grid reference can be given by a 10 km grid reference followed by a single letter (the letter O is skipped).
For more information see:
It could be useful if igr supported conversion from and to the tetrad from of grid reference, sometimes referred to as DINTY form of grid reference.