- earth-fixed systems applied to engineering activities on or near the surface of the earth;
- CRSs on moving platforms such as road vehicles, vessels, aircraft, or spacecraft.
Engineering CRSs used on moving platforms are usually intermediate coordinate reference systems that are computationally required to calculate coordinates referenced to geocentric, geographic or projected CRSs. These engineering coordinate reference systems are subject to all the motions of the platform with which they are associated. In this case "contextually local" means that the associated coordinates are meaningful only relative to the moving platform. Earth curvature is usually irrelevant and is therefore ignored. In the spatial sense their applicability may extend from the immediate vicinity of the platform (e.g. a moving seismic ship) to the entire earth (e.g. in space applications). The determining factor is the mathematical model deployed in the positioning calculations. Transformation of coordinates from these moving Engineering CRSs to earth-referenced coordinate reference systems involves time-dependent coordinate operation parameters.