| HL | HM | HN | HO | HP | JL | JM |
| HQ | HR | HS | HT | HU | JQ | JR |
| HV | HW | HX | HY | HZ | JV | JW
|
| NA | NB | NC | ND | NE | OA | OB |
| NF | NG | NH | NJ | NK | OF | OG |
| NL | NM | NN | NO | NP | OL | OM |
| NQ | NR | NS | NT | NU | OQ | OR |
| NV | NW | NX | NY | NZ | OV | OW
|
| SA | SB | SC | SD | SE | TA | TB |
| SF | SG | SH | SJ | SK | TF | TG |
| SL | SM | SN | SO | SP | TL | TM |
| SQ | SR | SS | ST | SU | TQ | TR |
| SV | SW | SX | SY | SZ | TV | TW
|
Within each square, eastings and northings are given as a code. For example, HL35 means 'square HL, 3 km east, 5 km north'. Additional precision is specified by longer numbers - SS390465 means 'square SS, 3900 metres east, 4650 meters north'.