A numeric coordinate pair or set (e.g., latitude and longitude, or projected easting/northing) that specifies a location on the Earth's surface within a defined geodetic reference system and projection, including the datum and epoch when required for unambiguous positioning.

Principle

A geographic coordinate is unambiguous only when accompanied by its geodetic reference system (datum), projection (if projected), and units; these metadata are required to transform, map or integrate coordinates reliably.

Demonstration

Illustrative scenario: Situation — An artifact is recorded with coordinates. Recognition — The recorder notes '37.1234°N, 2.3456°W, WGS84 (EPSG:4326)'. Action — GIS staff import the point using the specified CRS and overlay it on regional maps. Consequence — The location aligns correctly with other georeferenced datasets because the reference system and units were documented.

Misapplication

Entering latitude/longitude without specifying the datum or confusing decimal degrees with degrees/minutes/seconds; the semantic error is assuming numeric coordinates are self‑sufficient identifiers of place rather than values that require a reference system to be meaningful.

Consequence

Missing or inconsistent coordinate metadata produces mislocated points after reprojection, map misalignment, inability to integrate datasets, and potential misinterpretation of spatial relationships at site and landscape scales.

Reversal

For fine‑grained intra‑trench recording, local grid coordinates tied to a site origin may be preferable to global coordinates because they provide higher local precision and legibility for excavation staff; however, to situate the site regionally the local coordinates must be related to geographic coordinates via survey ties.

Boundary

Clearly within: a coordinate pair with an explicitly stated datum and projection. Boundary case: numeric coordinates recorded without datum noted. Clearly outside: verbal place descriptions or relative directions without numeric coordinates.

Semantic Tension

Global interoperability and locateability ↔ local measurement precision and operational convenience of site‑centric coordinate systems.

Synthesis

Geographic coordinates place field observations within a global spatial framework, but they become operationally useful only when the supporting geodetic metadata (datum, projection, units) are recorded so coordinates can be transformed and integrated without ambiguity.