Grid Sector
A grid sector is an unofficial name given for a part of the grid (or world map). The name was invented by the Geography Of Second Life group while editing List Of Microcontinents And Sim Clusters. The system proved to be very effective for map orientation.
Size
A grid sector is a square with 100 sims length and 100 sims wide. In kilometers, that is about 25.6/25.6 km. It looks like the Linden officials use something similar for the grid map. When you scale the map to lowest resolution, image does not form in the same moment for all the map. Image is formed for different parts of the map, parts that have shape of a square. This means that, at lowest resolution, grid map texture is saved in squares of about 100/100 sims.
Naming and coordinates
The only way to define the position of a structure on the map is by using Coordinates. The coordinates are similar to those used by Gridsurvey[1], in format longitude (min-max) /latitude (min-max) for a region of map and longitude/latitude for a single sim. The oldest sim, Da Boom, in Sansara, has coordinates 1000/1000.
Grid sectors are named with letters from left (West) to right (East) and with numbers from down (South) to up (North), exactly like the squares in a chess board. Theoretically, they start with grid sector A1 and end with T20. In practice, many grid sectors are in fact void sectors.
Using grid sectors
Unlike coordinates, grid sectors are much more simple to manage and to understand their position. It is a much easier way to find the position of a Continent, Subcontinent, Microcontinent, Sim Cluster, Sim Group or Isolated Sim using a grid sector.
See also
List Of Microcontinents And Sim Clusters - includes detalied data for all grid sectors
Oceans - additional information can be found here, including links to all oceans