When you hear for example 2389. The "2" means the North Region, the "3" means ranger unit number within that the North Region, and the 89 describes the unit type. The key for those unit types is described below.

Number	Unit Type
00-19	Chiefs, Division Cheifs & Battalion Cheifs
20-29	Prevention Units
30-39	Truck Companies & Utility Vechicals
40-49	Dozers
50-59	Utility Units
60-69	Can be called Type 3 Engines or Grass Units (Small 4x4 and in some district they handle Medical Aids & are called Squads)
70-79	Can be called Type 2 Engines or Brush Units (4x4, in some district they handle Medical Aids & are called Squads)
80-89	Type 1 Engine (City Street Engines, Primary structure response, Medical Aids)
90-99	Water Tenders & Engines