Rule 1
Preserve the observed geography.
Source data remain identified at their original grain. An FTC consumer Area Code remains an observed Area Code; a ZIP remains a ZIP.
The standard
The Standard / Methodology
A category becomes durable when its definitions, evidence rules and versioning are clear.
The NDS Area Code Market Standard™ defines the terms, governance, crosswalk roles, versioning and publication rules used by the NDS Area Code Market System™.
Rule 2
Separate observed, derived and modeled values.
A market-family total derived from observed Area Codes is not labeled the same way as a modeled ZIP allocation.
Rule 3
Version the market system.
Changes to market-family membership, crosswalk relationships or published definitions should create a new governed edition, with prior editions preserved.
Core standard vocabulary
| Term | NDS meaning |
|---|---|
| Area Code | Public telephone numbering identifier. |
| NDS Area Code Market | The governed analytical market identity. |
| NDS Area Code Market Family™ | One Area Code or an overlay-aware set of Area Codes governed as one market. |
| ZIP by NDS Area Code Market™ | The governed relationship layer connecting ZIP Codes with NDS market families. |
| City by NDS Area Code Market™ | The governed city-to-market-family relationship layer. |
Boundary note. NDS Area Code Markets are analytical/presentation geographies. They are not legal municipal, regulatory, census or telephone-carrier service boundaries.