Change term - geodeticDatum

[ArthurChapman]

Term change

• Submitter: @ArthurChapman on behalf of the Biodiversity Data Quality Interest Group TG2: Tests and Assertions
• Efficacy Justification (why is this change necessary?): The Georeferencing Best Practices (https://doi.org/10.15468/doc-gg7h-s853) recommends the use of "not recorded" rather than "unknown"
• Demand Justification (if the change is semantic in nature, name at least two organizations that independently need this term): It has implications in several tests for the proposed BDQ Standard - see comments under TG2-VALIDATION_GEODETICDATUM_STANDARD bdq#59 and TG2-AMENDMENT_GEODETICDATUM_STANDARDIZED bdq#60.
• Stability Justification (what concerns are there that this might affect existing implementations?): See Recommendations on missing/unknown/not recorded data in Darwin Core #437
• Implications for dwciri: namespace (does this change affect a dwciri term version)?: None

Current Term definition: https://dwc.tdwg.org/terms/#dwc:geodeticDatum

Proposed attributes of the new term version (Please put actual changes to be implemented in bold and strikethrough):

• Term name (in lowerCamelCase for properties, UpperCamelCase for classes): geodeticDatum
• Term label (English, not normative): Geodetic Datum
• Organized in Class (e.g., Occurrence, Event, Location, Taxon): Location
• Definition of the term (normative): The ellipsoid, geodetic datum, or spatial reference system (SRS) upon which the geographic coordinates given in dwc:decimalLatitude and dwc:decimalLongitude are based.
• Usage comments (recommendations regarding content, etc., not normative): Recommended best practice is to use the EPSG code of the SRS, if known. Otherwise use a controlled vocabulary for the name or code of the geodetic datum, if known. Otherwise use a controlled vocabulary for the name or code of the ellipsoid, if known. If none of these is known, use the value unknown not recorded. This term has an equivalent in the dwciri: namespace that allows only an IRI as a value, whereas this term allows for any string literal value.
• Examples (not normative): EPSG:4326epsg:4326; WGS84; NAD27; Campo Inchauspe; European 1950; Clarke 1866
unknown not recorded
• Refines (identifier of the broader term this term refines; normative): None
• Replaces (identifier of the existing term that would be deprecated and replaced by this term; normative): http://rs.tdwg.org/dwc/terms/version/geodeticDatum-2023-06-28
• ABCD 2.06 (XPATH of the equivalent term in ABCD or EFG; not normative): DataSets/DataSet/Units/Unit/Gathering/SiteCoordinateSets/SiteCoordinates/CoordinatesLatLon/SpatialDatum

[matdillen]

We proposed a vocabulary in a paper a few years ago (see table 2): https://doi.org/10.1093/database/baz129

For this value, it would fit either unknown:undigitized or unknown:missing. Would it make sense to align vocabularies for missing values, or at least include this distinction in the examples? It could be important from a digitization point of view.