A region type is what a region is called where it lies: a borough, a ward, a commune, an arrondissement, a Landkreis, a governorate. It is a label. It records the local term instead of translating it into a foreign one, so the word an authority and its residents use survives in the record.

Being a label is the difference from the region group. The group is structural: it fixes the tier, decides which parent is allowed, and is enforced on every save. The type carries no structure at all. Changing it renames what a reader sees and moves nothing.

A type belongs to exactly one tier, and a word that occurs on several tiers is several types. This catalogue holds "district" five times, as a first-level unit of a country, as a unit below that, as a city, as a first-level city district and as a second-level one; "county", "borough", "region" and "ward" repeat the same way. Which one applies follows from the tier the region sits on, which is why a type may never be chosen by matching the word alone.

Several types can share one definition where the concept is the same and only the tier differs, and they should: the text explains the term, not the row. What the type does not say is how the division was drawn, which is the division basis, or where the region sits, which is the region group.