rdblue commented on code in PR #15834: URL: https://github.com/apache/iceberg/pull/15834#discussion_r3169540813
########## format/spec.md: ########## @@ -242,10 +242,12 @@ For `geometry` type, the CRS does not affect geometric calculations, which are a The default CRS value `OGC:CRS84` means that the objects must be stored in longitude, latitude based on the WGS84 datum. -Custom CRS values can be specified by a string of the format `type:identifier`, where `type` is one of the following values: - -* `srid`: [Spatial reference identifier](https://en.wikipedia.org/wiki/Spatial_reference_system#Identifier), `identifier` is the SRID itself. -* `projjson`: [PROJJSON](https://proj.org/en/stable/specifications/projjson.html), `identifier` is the name of a table property where the projjson string is stored. +Non-default CRS values are specified by any string that uniquely identifies a coordinate reference system associated with this type. +To maximize interoperability, suggested formats for CRS include, but are not limited to: +* `<projjson>` - A complete CRS definition embedded directly using the [PROJJSON](https://proj.org/en/stable/specifications/projjson.html) specification. Example for `OGC:CRS83`: `{"$schema": "https://proj.org/schemas/v0.7/projjson.schema.json","type": "GeographicCRS","name": "NAD83 (CRS83)","datum": {"type": "GeodeticReferenceFrame"...` Review Comment: I'm not too bothered by ANY STRING. If we're being overly strict about wording, then it says the string should identify a CRS, not encode a CRS. If you feel like adding a statement to qualify this, you can: "any string that uniquely identifies a CRS (but is not a PROJJSON definition as stated below)". My guideline for these cases is to go for clarity and I don't think it is unclear. If someone later argues "hey, it said ANY STRING" despite a clear prohibition below, I would have no problem being firm that it was written incorrectly. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
