szehon-ho commented on code in PR #15834: URL: https://github.com/apache/iceberg/pull/15834#discussion_r3134530907
########## 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 (but not limited to) formats for CRS are: +* `<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 mean, one is on top, one is on bottom. Its much easier imho if they are next to each other, then one can read the link about projjson and then see the next one. now there's two places, two links. (popularity may be a bit harder to measure for now, but you may know more than me). Anyway just my 2c -- 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]
