Editing Natural Area Code (section)

== Two-dimensional system ==
Instead of numerical longitudes and latitudes, a grid with 30 rows and 30 columns - each cell denoted by the numbers 0-9 and the twenty consonants of the [[Latin alphabet]] - is laid over the flattened globe. A NAC cell (or block) can be subdivided repeatedly into smaller NAC grids to yield an arbitrarily small area, subject to the ±1&nbsp;m limitations of the [[World Geodetic System]] (WGS) data of 1984.

A NAC represents an area on the Earth—the longer the NAC, the smaller the area (and thereby, location) represented. A ten-character NAC can uniquely specify any [[building]], [[house]], or fixed object in the world. An eight-character NAC specifies an area no larger than 25 metres by 50 metres, while a ten-character NAC cell is no larger than 0.8 metres by 1.6 metres.

Using a [[base 30]] positional numeral system, NAC uses an alternate method which excludes vowels and avoids potential confusion between "0" (zero) and "O" (capital "o"), and "1" (one) and "I" (capital "i"):
{| class="wikitable"
|- align="right"
! Decimal
| 0 || 1 || 2 || 3 || 4 || 5 || 6 || 7 || 8 || 9 || 10 || 11 || 12 || 13 || 14
|- align="right"
! Base 30 
| 0 || 1 || 2 || 3 || 4 || 5 || 6 || 7 || 8 || 9 ||  B ||  C ||  D ||  F ||  G
|- 
| style="font: 0.5em/0.5em serif;" colspan="19" | &nbsp;
|- align="right"
! Decimal
| 15 || 16 || 17 || 18 || 19 || 20 || 21 || 22 || 23 || 24 || 25 || 26 || 27 || 28 || 29
|- align="right"
! Base 30 
|  H ||  J ||  K ||  L ||  M ||  N ||  P ||  Q ||  R ||  S ||  T ||  V ||  W ||  X ||  Z
|}
For example, the ten-character NAC for the centre of the city of [[Brussels]] is HBV6R&nbsp;RG77T.