Ooru is not the first grid-based addressing scheme, and most of its design decisions are reactions to specific properties of the existing ones.
| System | Hierarchical | Topological | Interpretable | Error behaviour |
|---|---|---|---|---|
| Ooru | Yes — 3 nested levels | Yes — adjacency computable | Yes — words are semantically ordered | Quiet: a wrong word lands nearby |
| what3words | No — one flat 3 m grid | No — neighbours unrelated by design | No — words are deliberately arbitrary | Loud: a wrong word lands on another continent |
| Open Location Code (Plus Codes) | Yes — each pair of characters refines | Partly — neighbours share a prefix | No — base-20 characters carry no meaning | Quiet, and hard to notice in an opaque code |
| Geohash | Yes — prefix refines | Poor — cells adjacent in space can differ in the first character | No | Quiet, with pathological jumps at cell boundaries |
| MGRS / UTM grid reference | Yes — digit pairs refine | Yes — genuinely metric | No — pure digits | Quiet; also unspeakable over a phone |
Against Plus Codes, which are the closest relative
Open Location Code already gets the two structural properties right: it is hierarchical and roughly topological, and it is an open standard with no licensing. If your requirement is a hierarchical grid code, use Plus Codes — that is the honest recommendation.
What Ooru adds is the thing a code cannot have: the identifier is memorable and its parts mean something. 7J4VXMV6+8Q and cavern.organza.panther name comparable areas, but only one survives being read aloud over a bad phone line, written on a parcel by hand, or recalled an hour later. And only one lets a reader form any mental picture of the region from the identifier alone.
The address space
For comparison, what3words needs 40,000³ = 64 trillion combinations to cover the planet at 3 m, which is why its vocabulary runs to 40,000 words per position and includes many that are hard to spell. Restricting to one metropolitan area is what makes a 920-word vocabulary of short, common, concrete nouns sufficient — and that restriction is the reason the words can be chosen for legibility rather than merely for count.