The dominant soil in a map unit is indicated by a symbol, eg TK for Te Kowhai.
Where different soils are intricately mixed or nearly equal in significance for a map unit, compound symbols are used:
- TK+B indicates the presence of two distinct soils (Te Kowhai and Bruntwood), the first of which is most abundant
- TK-B indicates a gradation from the most abundant soil (Te Kowhai) to another, slightly less abundant soil (Bruntwood).