PROJJSON: support additional properties allowed in id object (version, authority_citation, uri) for parity with WKT2:2019

14 files changed, 1161 insertions, 41 deletions

diff --git a/data/projjson.schema.json b/data/projjson.schema.json
index c347b3e1..6ed97b7b 100644
--- a/data/projjson.schema.json
+++ b/data/projjson.schema.json
@@ -1,7 +1,7 @@
 {
-  "$id": "https://proj.org/schemas/v0.3/projjson.schema.json",
+  "$id": "https://proj.org/schemas/v0.4/projjson.schema.json",
   "$schema": "http://json-schema.org/draft-07/schema#",
-  "description": "Schema for PROJJSON (v0.3)",
+  "description": "Schema for PROJJSON (v0.4)",
   "$comment": "This file exists both in data/ and in schemas/vXXX/. Keep both in sync. And if changing the value of $id, change PROJJSON_CURRENT_VERSION accordingly in io.cpp",
 
   "oneOf": [
@@ -612,7 +612,12 @@
         "authority": { "type": "string" },
         "code": {
           "oneOf": [ { "type": "string" }, { "type": "integer" } ]
-        }
+        },
+        "version": {
+          "oneOf": [ { "type": "string" }, { "type": "number" } ]
+        },
+        "authority_citation": { "type": "string" },
+        "uri": { "type": "string" }
       },
       "required" : [ "authority", "code" ],
       "additionalProperties": false
diff --git a/docs/source/apps/cct.rst b/docs/source/apps/cct.rst
index 75d67972..08bdd004 100644
--- a/docs/source/apps/cct.rst
+++ b/docs/source/apps/cct.rst
@@ -29,7 +29,7 @@ by :c:func:`proj_create`, provided it expresses a coordinate operation
       uniqueness is not guaranteed, heuristics are applied to determine the appropriate best match.
     - a OGC URN combining references for concatenated operations
       (e.g. "urn:ogc:def:coordinateOperation,coordinateOperation:EPSG::3895,coordinateOperation:EPSG::1618")
-    - a PROJJSON string. The jsonschema is at https://proj.org/schemas/v0.3/projjson.schema.json
+    - a PROJJSON string. The jsonschema is at https://proj.org/schemas/v0.4/projjson.schema.json
 
     .. versionadded:: 8.0.0
 
diff --git a/docs/source/apps/cs2cs.rst b/docs/source/apps/cs2cs.rst
index 00443d9c..841ce092 100644
--- a/docs/source/apps/cs2cs.rst
+++ b/docs/source/apps/cs2cs.rst
@@ -35,7 +35,7 @@ Synopsis
       (*added in 6.2*)
     - a OGC URN combining references for concatenated operations
       (e.g. "urn:ogc:def:coordinateOperation,coordinateOperation:EPSG::3895,coordinateOperation:EPSG::1618")
-    - a PROJJSON string. The jsonschema is at https://proj.org/schemas/v0.3/projjson.schema.json (*added in 6.2*)
+    - a PROJJSON string. The jsonschema is at https://proj.org/schemas/v0.4/projjson.schema.json (*added in 6.2*)
     - a compound CRS made from two object names separated with " + ". e.g. "WGS 84 + EGM96 height" (*added in 7.1*)
 
     .. versionadded:: 6.0.0
diff --git a/docs/source/apps/projinfo.rst b/docs/source/apps/projinfo.rst
index f9445f1b..04ee7578 100644
--- a/docs/source/apps/projinfo.rst
+++ b/docs/source/apps/projinfo.rst
@@ -55,7 +55,7 @@ Synopsis
       (*added in 6.2*)
     - a OGC URN combining references for concatenated operations
       (e.g. "urn:ogc:def:coordinateOperation,coordinateOperation:EPSG::3895,coordinateOperation:EPSG::1618")
-    - a PROJJSON string. The jsonschema is at https://proj.org/schemas/v0.3/projjson.schema.json (*added in 6.2*)
+    - a PROJJSON string. The jsonschema is at https://proj.org/schemas/v0.4/projjson.schema.json (*added in 6.2*)
     - a compound CRS made from two object names separated with " + ". e.g. "WGS 84 + EGM96 height" (*added in 7.1*)
 
     {object_reference} is a filename preceded by the '@' character.  The
diff --git a/docs/source/development/reference/functions.rst b/docs/source/development/reference/functions.rst
index 142c7ca9..10bb07d0 100644
--- a/docs/source/development/reference/functions.rst
+++ b/docs/source/development/reference/functions.rst
@@ -52,7 +52,7 @@ paragraph for more details.
       syntax "EPSG:2393+5717"),
     - a OGC URN combining references for concatenated operations
       (e.g. "urn:ogc:def:coordinateOperation,coordinateOperation:EPSG::3895,coordinateOperation:EPSG::1618")
-    - a PROJJSON string. The jsonschema is at https://proj.org/schemas/v0.3/projjson.schema.json (*added in 6.2*)
+    - a PROJJSON string. The jsonschema is at https://proj.org/schemas/v0.4/projjson.schema.json (*added in 6.2*)
     - a compound CRS made from two object names separated with " + ". e.g. "WGS 84 + EGM96 height" (*added in 7.1*)
 
     Example call:
diff --git a/docs/source/specifications/projjson.rst b/docs/source/specifications/projjson.rst
index 13ef19b5..c2280c0b 100644
--- a/docs/source/specifications/projjson.rst
+++ b/docs/source/specifications/projjson.rst
@@ -13,17 +13,18 @@ the same as WKT2:2019.
 
 PROJJSON is available as input and output of PROJ since PROJ 6.2.
 
-The current version is 0.3.
+The current version is 0.4.
 
 Schema
 ------
 
 A JSON schema of its grammar is available at
-https://proj.org/schemas/v0.3/projjson.schema.json
+https://proj.org/schemas/v0.4/projjson.schema.json
 
 History
 -------
 
+* v0.4: additional properties allowed in id object (version, authority_citation, uri)
 * v0.3: additional properties allowed in BoundCRS object (name, scope, area, bbox, usages, remarks, id, ids)
 * v0.2: addition of geoid_model in VerticalCRS object.
 * v0.1: initial version for PROJ 6.2
diff --git a/include/proj/io.hpp b/include/proj/io.hpp
index 1c858248..b07f55ff 100644
--- a/include/proj/io.hpp
+++ b/include/proj/io.hpp
@@ -540,8 +540,7 @@ class PROJ_GCC_DLL JSONFormatter {
     PROJ_INTERNAL bool
     outputUsage(bool calledBeforeObjectContext = false) const;
 
-    PROJ_INTERNAL static const char *PROJJSON_v0_2;
-    PROJ_INTERNAL static const char *PROJJSON_v0_3;
+    PROJ_INTERNAL static const char *PROJJSON_v0_4;
 
     //! @endcond
 
diff --git a/schemas/v0.4/projjson.schema.json b/schemas/v0.4/projjson.schema.json
new file mode 100644
index 00000000..6ed97b7b
--- /dev/null
+++ b/schemas/v0.4/projjson.schema.json
@@ -0,0 +1,1002 @@
+{
+  "$id": "https://proj.org/schemas/v0.4/projjson.schema.json",
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "description": "Schema for PROJJSON (v0.4)",
+  "$comment": "This file exists both in data/ and in schemas/vXXX/. Keep both in sync. And if changing the value of $id, change PROJJSON_CURRENT_VERSION accordingly in io.cpp",
+
+  "oneOf": [
+    { "$ref": "#/definitions/crs" },
+    { "$ref": "#/definitions/datum" },
+    { "$ref": "#/definitions/datum_ensemble" },
+    { "$ref": "#/definitions/ellipsoid" },
+    { "$ref": "#/definitions/prime_meridian" },
+    { "$ref": "#/definitions/single_operation" },
+    { "$ref": "#/definitions/concatenated_operation" }
+  ],
+
+  "definitions": {
+
+    "abridged_transformation": {
+      "type": "object",
+      "properties": {
+        "$schema" : { "type": "string" },
+        "type": { "type": "string", "enum": ["AbridgedTransformation"] },
+        "name": { "type": "string" },
+        "method": { "$ref": "#/definitions/method" },
+        "parameters": {
+            "type": "array",
+            "items": { "$ref": "#/definitions/parameter_value" }
+        },
+        "id": { "$ref": "#/definitions/id" },
+        "ids": { "$ref": "#/definitions/ids" }
+      },
+      "required" : [ "name", "method", "parameters" ],
+      "allOf": [
+        { "$ref": "#/definitions/id_ids_mutually_exclusive" }
+      ],
+      "additionalProperties": false
+    },
+
+    "axis": {
+      "type": "object",
+      "properties": {
+        "$schema" : { "type": "string" },
+        "type": { "type": "string", "enum": ["Axis"] },
+        "name": { "type": "string" },
+        "abbreviation": { "type": "string" },
+        "direction": { "type": "string",
+                       "enum": [ "north",
+                                 "northNorthEast",
+                                 "northEast",
+                                 "eastNorthEast",
+                                 "east",
+                                 "eastSouthEast",
+                                 "southEast",
+                                 "southSouthEast",
+                                 "south",
+                                 "southSouthWest",
+                                 "southWest",
+                                 "westSouthWest",
+                                 "west",
+                                 "westNorthWest",
+                                 "northWest",
+                                 "northNorthWest",
+                                 "up",
+                                 "down",
+                                 "geocentricX",
+                                 "geocentricY",
+                                 "geocentricZ",
+                                 "columnPositive",
+                                 "columnNegative",
+                                 "rowPositive",
+                                 "rowNegative",
+                                 "displayRight",
+                                 "displayLeft",
+                                 "displayUp",
+                                 "displayDown",
+                                 "forward",
+                                 "aft",
+                                 "port",
+                                 "starboard",
+                                 "clockwise",
+                                 "counterClockwise",
+                                 "towards",
+                                 "awayFrom",
+                                 "future",
+                                 "past",
+                                 "unspecified" ] },
+        "unit": { "$ref": "#/definitions/unit" },
+        "id": { "$ref": "#/definitions/id" },
+        "ids": { "$ref": "#/definitions/ids" }
+      },
+      "required" : [ "name", "abbreviation", "direction" ],
+      "allOf": [
+        { "$ref": "#/definitions/id_ids_mutually_exclusive" }
+      ],
+      "additionalProperties": false
+    },
+
+    "bbox": {
+      "type": "object",
+      "properties": {
+        "east_longitude": { "type": "number" },
+        "west_longitude": { "type": "number" },
+        "south_latitude": { "type": "number" },
+        "north_latitude": { "type": "number" }
+      },
+      "required" : [ "east_longitude", "west_longitude",
+                     "south_latitude", "north_latitude" ],
+      "additionalProperties": false
+    },
+
+    "bound_crs": {
+      "type": "object",
+      "allOf": [{ "$ref": "#/definitions/object_usage" }],
+      "properties": {
+        "$schema" : { "type": "string" },
+        "type": { "type": "string", "enum": ["BoundCRS"] },
+        "name": { "type": "string" },
+        "source_crs": { "$ref": "#/definitions/crs" },
+        "target_crs": { "$ref": "#/definitions/crs" },
+        "transformation": { "$ref": "#/definitions/abridged_transformation" },
+        "scope": {},
+        "area": {},
+        "bbox": {},
+        "usages": {},
+        "remarks": {},
+        "id": {}, "ids": {}
+     },
+     "required" : [ "source_crs", "target_crs", "transformation" ],
+     "additionalProperties": false
+    },
+
+    "compound_crs": {
+      "type": "object",
+      "allOf": [{ "$ref": "#/definitions/object_usage" }],
+      "properties": {
+        "type": { "type": "string", "enum": ["CompoundCRS"] },
+        "name": { "type": "string" },
+        "components":  {
+           "type": "array",
+            "items": { "$ref": "#/definitions/crs" }
+        },
+        "$schema" : {},
+        "scope": {},
+        "area": {},
+        "bbox": {},
+        "usages": {},
+        "remarks": {},
+        "id": {}, "ids": {}
+      },
+      "required" : [ "name", "components" ],
+      "additionalProperties": false
+    },
+
+    "concatenated_operation": {
+      "type": "object",
+      "allOf": [{ "$ref": "#/definitions/object_usage" }],
+      "properties": {
+        "type": { "type": "string", "enum": ["ConcatenatedOperation"] },
+        "name": { "type": "string" },
+        "source_crs": { "$ref": "#/definitions/crs" },
+        "target_crs": { "$ref": "#/definitions/crs" },
+        "steps":  {
+           "type": "array",
+            "items": { "$ref": "#/definitions/single_operation" }
+        },
+        "$schema" : {},
+        "scope": {},
+        "area": {},
+        "bbox": {},
+        "usages": {},
+        "remarks": {},
+        "id": {}, "ids": {}
+      },
+      "required" : [ "name", "source_crs", "target_crs", "steps" ],
+      "additionalProperties": false
+    },
+
+    "conversion": {
+      "type": "object",
+      "properties": {
+        "$schema" : { "type": "string" },
+        "type": { "type": "string", "enum": ["Conversion"] },
+        "name": { "type": "string" },
+        "method": { "$ref": "#/definitions/method" },
+        "parameters": {
+            "type": "array",
+            "items": { "$ref": "#/definitions/parameter_value" }
+        },
+        "id": { "$ref": "#/definitions/id" },
+        "ids": { "$ref": "#/definitions/ids" }
+      },
+      "required" : [ "name", "method" ],
+      "allOf": [
+        { "$ref": "#/definitions/id_ids_mutually_exclusive" }
+      ],
+      "additionalProperties": false
+    },
+
+    "coordinate_system": {
+      "type": "object",
+      "properties": {
+        "$schema" : { "type": "string" },
+        "type": { "type": "string", "enum": ["CoordinateSystem"] },
+        "name": { "type": "string" },
+        "subtype": { "type": "string",
+                     "enum": ["Cartesian",
+                              "spherical",
+                              "ellipsoidal",
+                              "vertical",
+                              "ordinal",
+                              "parametric",
+                              "TemporalDateTime",
+                              "TemporalCount",
+                              "TemporalMeasure"]  },
+        "axis": {
+            "type": "array",
+            "items": { "$ref": "#/definitions/axis" }
+        },
+        "id": { "$ref": "#/definitions/id" },
+        "ids": { "$ref": "#/definitions/ids" }
+      },
+      "required" : [ "subtype", "axis" ],
+      "allOf": [
+        { "$ref": "#/definitions/id_ids_mutually_exclusive" }
+      ],
+      "additionalProperties": false
+    },
+
+    "crs": {
+      "oneOf": [
+        { "$ref": "#/definitions/bound_crs" },
+        { "$ref": "#/definitions/compound_crs" },
+        { "$ref": "#/definitions/derived_engineering_crs" },
+        { "$ref": "#/definitions/derived_geodetic_crs" },
+        { "$ref": "#/definitions/derived_parametric_crs" },
+        { "$ref": "#/definitions/derived_projected_crs" },
+        { "$ref": "#/definitions/derived_temporal_crs" },
+        { "$ref": "#/definitions/derived_vertical_crs" },
+        { "$ref": "#/definitions/engineering_crs" },
+        { "$ref": "#/definitions/geodetic_crs" },
+        { "$ref": "#/definitions/parametric_crs" },
+        { "$ref": "#/definitions/projected_crs" },
+        { "$ref": "#/definitions/temporal_crs" },
+        { "$ref": "#/definitions/vertical_crs" }
+      ]
+    },
+
+    "datum": {
+      "oneOf": [
+        { "$ref": "#/definitions/geodetic_reference_frame" },
+        { "$ref": "#/definitions/vertical_reference_frame" },
+        { "$ref": "#/definitions/dynamic_geodetic_reference_frame" },
+        { "$ref": "#/definitions/dynamic_vertical_reference_frame" },
+        { "$ref": "#/definitions/temporal_datum" },
+        { "$ref": "#/definitions/parametric_datum" },
+        { "$ref": "#/definitions/engineering_datum" }
+      ]
+    },
+
+    "datum_ensemble": {
+      "type": "object",
+      "properties": {
+        "$schema" : { "type": "string" },
+        "type": { "type": "string", "enum": ["DatumEnsemble"] },
+        "name": { "type": "string" },
+        "members": {
+            "type": "array",
+            "items": {
+                "type": "object",
+                "properties": {
+                    "name": { "type": "string" },
+                    "id": { "$ref": "#/definitions/id" },
+                    "ids": { "$ref": "#/definitions/ids" }
+                },
+                "required" : [ "name" ],
+                "allOf": [
+                    { "$ref": "#/definitions/id_ids_mutually_exclusive" }
+                ],
+                "additionalProperties": false
+            }
+        },
+        "ellipsoid": { "$ref": "#/definitions/ellipsoid" },
+        "accuracy": { "type": "string" },
+        "id": { "$ref": "#/definitions/id" },
+        "ids": { "$ref": "#/definitions/ids" }
+      },
+      "required" : [ "name", "members", "accuracy" ],
+      "allOf": [
+        { "$ref": "#/definitions/id_ids_mutually_exclusive" }
+      ],
+      "additionalProperties": false
+    },
+
+    "derived_engineering_crs": {
+      "type": "object",
+      "allOf": [{ "$ref": "#/definitions/object_usage" }],
+      "properties": {
+        "type": { "type": "string",
+                  "enum": ["DerivedEngineeringCRS"] },
+        "name": { "type": "string" },
+        "base_crs": { "$ref": "#/definitions/engineering_crs" },
+        "conversion": { "$ref": "#/definitions/conversion" },
+        "coordinate_system": { "$ref": "#/definitions/coordinate_system" },
+        "$schema" : {},
+        "scope": {},
+        "area": {},
+        "bbox": {},
+        "usages": {},
+        "remarks": {},
+        "id": {}, "ids": {}
+     },
+     "required" : [ "name", "base_crs", "conversion", "coordinate_system" ],
+     "additionalProperties": false
+    },
+
+    "derived_geodetic_crs": {
+      "type": "object",
+      "allOf": [{ "$ref": "#/definitions/object_usage" }],
+      "properties": {
+        "type": { "type": "string",
+                  "enum": ["DerivedGeodeticCRS",
+                           "DerivedGeographicCRS"] },
+        "name": { "type": "string" },
+        "base_crs": { "$ref": "#/definitions/geodetic_crs" },
+        "conversion": { "$ref": "#/definitions/conversion" },
+        "coordinate_system": { "$ref": "#/definitions/coordinate_system" },
+        "$schema" : {},
+        "scope": {},
+        "area": {},
+        "bbox": {},
+        "usages": {},
+        "remarks": {},
+        "id": {}, "ids": {}
+     },
+     "required" : [ "name", "base_crs", "conversion", "coordinate_system" ],
+     "additionalProperties": false
+    },
+
+    "derived_parametric_crs": {
+      "type": "object",
+      "allOf": [{ "$ref": "#/definitions/object_usage" }],
+      "properties": {
+        "type": { "type": "string",
+                  "enum": ["DerivedParametricCRS"] },
+        "name": { "type": "string" },
+        "base_crs": { "$ref": "#/definitions/parametric_crs" },
+        "conversion": { "$ref": "#/definitions/conversion" },
+        "coordinate_system": { "$ref": "#/definitions/coordinate_system" },
+        "$schema" : {},
+        "scope": {},
+        "area": {},
+        "bbox": {},
+        "usages": {},
+        "remarks": {},
+        "id": {}, "ids": {}
+     },
+     "required" : [ "name", "base_crs", "conversion", "coordinate_system" ],
+     "additionalProperties": false
+    },
+
+    "derived_projected_crs": {
+      "type": "object",
+      "allOf": [{ "$ref": "#/definitions/object_usage" }],
+      "properties": {
+        "type": { "type": "string",
+                  "enum": ["DerivedProjectedCRS"] },
+        "name": { "type": "string" },
+        "base_crs": { "$ref": "#/definitions/projected_crs" },
+        "conversion": { "$ref": "#/definitions/conversion" },
+        "coordinate_system": { "$ref": "#/definitions/coordinate_system" },
+        "$schema" : {},
+        "scope": {},
+        "area": {},
+        "bbox": {},
+        "usages": {},
+        "remarks": {},
+        "id": {}, "ids": {}
+     },
+     "required" : [ "name", "base_crs", "conversion", "coordinate_system" ],
+     "additionalProperties": false
+    },
+
+    "derived_temporal_crs": {
+      "type": "object",
+      "allOf": [{ "$ref": "#/definitions/object_usage" }],
+      "properties": {
+        "type": { "type": "string",
+                  "enum": ["DerivedTemporalCRS"] },
+        "name": { "type": "string" },
+        "base_crs": { "$ref": "#/definitions/temporal_crs" },
+        "conversion": { "$ref": "#/definitions/conversion" },
+        "coordinate_system": { "$ref": "#/definitions/coordinate_system" },
+        "$schema" : {},
+        "scope": {},
+        "area": {},
+        "bbox": {},
+        "usages": {},
+        "remarks": {},
+        "id": {}, "ids": {}
+     },
+     "required" : [ "name", "base_crs", "conversion", "coordinate_system" ],
+     "additionalProperties": false
+    },
+
+    "derived_vertical_crs": {
+      "type": "object",
+      "allOf": [{ "$ref": "#/definitions/object_usage" }],
+      "properties": {
+        "type": { "type": "string",
+                  "enum": ["DerivedVerticalCRS"] },
+        "name": { "type": "string" },
+        "base_crs": { "$ref": "#/definitions/vertical_crs" },
+        "conversion": { "$ref": "#/definitions/conversion" },
+        "coordinate_system": { "$ref": "#/definitions/coordinate_system" },
+        "$schema" : {},
+        "scope": {},
+        "area": {},
+        "bbox": {},
+        "usages": {},
+        "remarks": {},
+        "id": {}, "ids": {}
+     },
+     "required" : [ "name", "base_crs", "conversion", "coordinate_system" ],
+     "additionalProperties": false
+    },
+
+    "dynamic_geodetic_reference_frame": {
+      "type": "object",
+      "allOf": [{ "$ref": "#/definitions/geodetic_reference_frame" }],
+      "properties": {
+        "type": { "type": "string", "enum": ["DynamicGeodeticReferenceFrame"] },
+        "name": {},
+        "anchor": {},
+        "ellipsoid": {},
+        "prime_meridian": {},
+        "frame_reference_epoch": { "type": "number" },
+        "deformation_model": { "type": "string" },
+        "$schema" : {},
+        "scope": {},
+        "area": {},
+        "bbox": {},
+        "usages": {},
+        "remarks": {},
+        "id": {}, "ids": {}
+      },
+      "required" : [ "name", "ellipsoid", "frame_reference_epoch" ],
+      "additionalProperties": false
+    },
+
+    "dynamic_vertical_reference_frame": {
+      "type": "object",
+      "allOf": [{ "$ref": "#/definitions/vertical_reference_frame" }],
+      "properties": {
+        "type": { "type": "string", "enum": ["DynamicVerticalReferenceFrame"] },
+        "name": {},
+        "anchor": {},
+        "frame_reference_epoch": { "type": "number" },
+        "deformation_model": { "type": "string" },
+        "$schema" : {},
+        "scope": {},
+        "area": {},
+        "bbox": {},
+        "usages": {},
+        "remarks": {},
+        "id": {}, "ids": {}
+      },
+      "required" : [ "name", "frame_reference_epoch" ],
+      "additionalProperties": false
+    },
+
+    "ellipsoid": {
+      "type": "object",
+      "oneOf":[
+        {
+          "properties": {
+            "$schema" : { "type": "string" },
+            "type": { "type": "string", "enum": ["Ellipsoid"] },
+            "name": { "type": "string" },
+            "semi_major_axis": { "$ref": "#/definitions/value_in_metre_or_value_and_unit" },
+            "semi_minor_axis": { "$ref": "#/definitions/value_in_metre_or_value_and_unit" },
+            "id": { "$ref": "#/definitions/id" },
+            "ids": { "$ref": "#/definitions/ids" }
+          },
+          "required" : [ "name", "semi_major_axis", "semi_minor_axis" ],
+          "additionalProperties": false
+        },
+        {
+          "properties": {
+            "$schema" : { "type": "string" },
+            "type": { "type": "string", "enum": ["Ellipsoid"] },
+            "name": { "type": "string" },
+            "semi_major_axis": { "$ref": "#/definitions/value_in_metre_or_value_and_unit" },
+            "inverse_flattening": { "type": "number" },
+            "id": { "$ref": "#/definitions/id" },
+           "ids": { "$ref": "#/definitions/ids" }
+          },
+          "required" : [ "name", "semi_major_axis", "inverse_flattening" ],
+          "additionalProperties": false
+        },
+        {
+          "properties": {
+            "$schema" : { "type": "string" },
+            "type": { "type": "string", "enum": ["Ellipsoid"] },
+            "name": { "type": "string" },
+            "radius": { "$ref": "#/definitions/value_in_metre_or_value_and_unit" },
+            "id": { "$ref": "#/definitions/id" },
+            "ids": { "$ref": "#/definitions/ids" }
+          },
+          "required" : [ "name", "radius" ],
+         "additionalProperties": false
+        }
+      ],
+      "allOf": [
+        { "$ref": "#/definitions/id_ids_mutually_exclusive" }
+      ]
+    },
+
+    "engineering_crs": {
+      "type": "object",
+      "allOf": [{ "$ref": "#/definitions/object_usage" }],
+      "properties": {
+        "type": { "type": "string", "enum": ["EngineeringCRS"] },
+        "name": { "type": "string" },
+        "datum": { "$ref": "#/definitions/engineering_datum" },
+        "coordinate_system": { "$ref": "#/definitions/coordinate_system" },
+        "$schema" : {},
+        "scope": {},
+        "area": {},
+        "bbox": {},
+        "usages": {},
+        "remarks": {},
+        "id": {}, "ids": {}
+      },
+      "required" : [ "name", "datum" ],
+      "additionalProperties": false
+    },
+
+    "engineering_datum": {
+      "type": "object",
+      "allOf": [{ "$ref": "#/definitions/object_usage" }],
+      "properties": {
+        "type": { "type": "string", "enum": ["EngineeringDatum"] },
+        "name": { "type": "string" },
+        "anchor": { "type": "string" },
+        "$schema" : {},
+        "scope": {},
+        "area": {},
+        "bbox": {},
+        "usages": {},
+        "remarks": {},
+        "id": {}, "ids": {}
+      },
+      "required" : [ "name" ],
+      "additionalProperties": false
+    },
+
+    "geodetic_crs": {
+      "type": "object",
+      "properties": {
+        "type": { "type": "string", "enum": ["GeodeticCRS", "GeographicCRS"] },
+        "name": { "type": "string" },
+        "datum": {
+            "oneOf": [
+                { "$ref": "#/definitions/geodetic_reference_frame" },
+                { "$ref": "#/definitions/dynamic_geodetic_reference_frame" }
+            ]
+        },
+        "datum_ensemble": { "$ref": "#/definitions/datum_ensemble" },
+        "coordinate_system": { "$ref": "#/definitions/coordinate_system" },
+        "$schema" : {},
+        "scope": {},
+        "area": {},
+        "bbox": {},
+        "usages": {},
+        "remarks": {},
+        "id": {}, "ids": {}
+      },
+      "required" : [ "name" ],
+      "description": "One and only one of datum and datum_ensemble must be provided",
+      "allOf": [
+        { "$ref": "#/definitions/object_usage" },
+        { "$ref": "#/definitions/one_and_only_one_of_datum_or_datum_ensemble" }
+      ],
+      "additionalProperties": false
+    },
+
+    "geodetic_reference_frame": {
+      "type": "object",
+      "allOf": [{ "$ref": "#/definitions/object_usage" }],
+      "properties": {
+        "type": { "type": "string", "enum": ["GeodeticReferenceFrame"] },
+        "name": { "type": "string" },
+        "anchor": { "type": "string" },
+        "ellipsoid": { "$ref": "#/definitions/ellipsoid" },
+        "prime_meridian": { "$ref": "#/definitions/prime_meridian" },
+        "$schema" : {},
+        "scope": {},
+        "area": {},
+        "bbox": {},
+        "usages": {},
+        "remarks": {},
+        "id": {}, "ids": {}
+      },
+      "required" : [ "name", "ellipsoid" ],
+      "additionalProperties": false
+    },
+
+    "id": {
+      "type": "object",
+      "properties": {
+        "authority": { "type": "string" },
+        "code": {
+          "oneOf": [ { "type": "string" }, { "type": "integer" } ]
+        },
+        "version": {
+          "oneOf": [ { "type": "string" }, { "type": "number" } ]
+        },
+        "authority_citation": { "type": "string" },
+        "uri": { "type": "string" }
+      },
+      "required" : [ "authority", "code" ],
+      "additionalProperties": false
+    },
+
+    "ids": {
+      "type": "array",
+      "items": { "$ref": "#/definitions/id" }
+    },
+
+    "method": {
+      "type": "object",
+      "properties": {
+        "$schema" : { "type": "string" },
+        "type": { "type": "string", "enum": ["OperationMethod"]},
+        "name": { "type": "string" },
+        "id": { "$ref": "#/definitions/id" },
+        "ids": { "$ref": "#/definitions/ids" }
+      },
+      "required" : [ "name" ],
+      "allOf": [
+        { "$ref": "#/definitions/id_ids_mutually_exclusive" }
+      ],
+      "additionalProperties": false
+    },
+
+    "id_ids_mutually_exclusive": {
+        "not": {
+            "type": "object",
+            "required": [ "id", "ids" ]
+        }
+    },
+
+    "one_and_only_one_of_datum_or_datum_ensemble": {
+      "allOf": [
+        {
+            "not": {
+                "type": "object",
+                "required": [ "datum", "datum_ensemble" ]
+            }
+        },
+        {
+            "oneOf": [
+                { "type": "object", "required": ["datum"] },
+                { "type": "object", "required": ["datum_ensemble"] }
+            ]
+        }
+      ]
+    },
+
+    "object_usage": {
+      "anyOf": [
+      {
+        "type": "object",
+        "properties": {
+            "$schema" : { "type": "string" },
+            "scope": { "type": "string" },
+            "area": { "type": "string" },
+            "bbox": { "$ref": "#/definitions/bbox" },
+            "remarks": { "type": "string" },
+            "id": { "$ref": "#/definitions/id" },
+            "ids": { "$ref": "#/definitions/ids" }
+        },
+        "allOf": [
+            { "$ref": "#/definitions/id_ids_mutually_exclusive" }
+        ]
+      },
+      {
+        "type": "object",
+        "properties": {
+            "$schema" : { "type": "string" },
+            "usages": { "$ref": "#/definitions/usages" },
+            "remarks": { "type": "string" },
+            "id": { "$ref": "#/definitions/id" },
+            "ids": { "$ref": "#/definitions/ids" }
+        },
+        "allOf": [
+            { "$ref": "#/definitions/id_ids_mutually_exclusive" }
+        ]
+      }
+      ]
+    },
+
+    "parameter_value": {
+      "type": "object",
+      "properties": {
+        "$schema" : { "type": "string" },
+        "type": { "type": "string", "enum": ["ParameterValue"] },
+        "name": { "type": "string" },
+        "value": {
+          "oneOf": [
+            { "type": "string" },
+            { "type": "number" }
+           ]
+        },
+        "unit": { "$ref": "#/definitions/unit" },
+        "id": { "$ref": "#/definitions/id" },
+        "ids": { "$ref": "#/definitions/ids" }
+      },
+      "required" : [ "name", "value" ],
+      "allOf": [
+        { "$ref": "#/definitions/id_ids_mutually_exclusive" }
+      ],
+      "additionalProperties": false
+    },
+
+    "parametric_crs": {
+      "type": "object",
+      "allOf": [{ "$ref": "#/definitions/object_usage" }],
+      "properties": {
+        "type": { "type": "string", "enum": ["ParametricCRS"] },
+        "name": { "type": "string" },
+        "datum": { "$ref": "#/definitions/parametric_datum" },
+        "coordinate_system": { "$ref": "#/definitions/coordinate_system" },
+        "$schema" : {},
+        "scope": {},
+        "area": {},
+        "bbox": {},
+        "usages": {},
+        "remarks": {},
+        "id": {}, "ids": {}
+      },
+      "required" : [ "name", "datum" ],
+      "additionalProperties": false
+    },
+
+    "parametric_datum": {
+      "type": "object",
+      "allOf": [{ "$ref": "#/definitions/object_usage" }],
+      "properties": {
+        "type": { "type": "string", "enum": ["ParametricDatum"] },
+        "name": { "type": "string" },
+        "anchor": { "type": "string" },
+        "$schema" : {},
+        "scope": {},
+        "area": {},
+        "bbox": {},
+        "usages": {},
+        "remarks": {},
+        "id": {}, "ids": {}
+      },
+      "required" : [ "name" ],
+      "additionalProperties": false
+    },
+
+    "prime_meridian": {
+      "type": "object",
+      "properties": {
+        "$schema" : { "type": "string" },
+        "type": { "type": "string", "enum": ["PrimeMeridian"] },
+        "name": { "type": "string" },
+        "longitude": { "$ref": "#/definitions/value_in_degree_or_value_and_unit" },
+        "id": { "$ref": "#/definitions/id" },
+        "ids": { "$ref": "#/definitions/ids" }
+      },
+      "required" : [ "name" ],
+      "allOf": [
+        { "$ref": "#/definitions/id_ids_mutually_exclusive" }
+      ],
+      "additionalProperties": false
+    },
+
+    "single_operation": {
+      "oneOf": [
+        { "$ref": "#/definitions/conversion" },
+        { "$ref": "#/definitions/transformation" }
+      ]
+    },
+
+    "projected_crs": {
+      "type": "object",
+      "allOf": [{ "$ref": "#/definitions/object_usage" }],
+      "properties": {
+        "type": { "type": "string",
+                  "enum": ["ProjectedCRS"] },
+        "name": { "type": "string" },
+        "base_crs": { "$ref": "#/definitions/geodetic_crs" },
+        "conversion": { "$ref": "#/definitions/conversion" },
+        "coordinate_system": { "$ref": "#/definitions/coordinate_system" },
+        "$schema" : {},
+        "scope": {},
+        "area": {},
+        "bbox": {},
+        "usages": {},
+        "remarks": {},
+        "id": {}, "ids": {}
+     },
+     "required" : [ "name", "base_crs", "conversion", "coordinate_system" ],
+     "additionalProperties": false
+    },
+
+    "temporal_crs": {
+      "type": "object",
+      "allOf": [{ "$ref": "#/definitions/object_usage" }],
+      "properties": {
+        "type": { "type": "string", "enum": ["TemporalCRS"] },
+        "name": { "type": "string" },
+        "datum": { "$ref": "#/definitions/temporal_datum" },
+        "coordinate_system": { "$ref": "#/definitions/coordinate_system" },
+        "$schema" : {},
+        "scope": {},
+        "area": {},
+        "bbox": {},
+        "usages": {},
+        "remarks": {},
+        "id": {}, "ids": {}
+      },
+      "required" : [ "name", "datum" ],
+      "additionalProperties": false
+    },
+
+    "temporal_datum": {
+      "type": "object",
+      "allOf": [{ "$ref": "#/definitions/object_usage" }],
+      "properties": {
+        "type": { "type": "string", "enum": ["TemporalDatum"] },
+        "name": { "type": "string" },
+        "calendar": { "type": "string" },
+        "time_origin": { "type": "string" },
+        "$schema" : {},
+        "scope": {},
+        "area": {},
+        "bbox": {},
+        "usages": {},
+        "remarks": {},
+        "id": {}, "ids": {}
+      },
+      "required" : [ "name", "calendar" ],
+      "additionalProperties": false
+    },
+
+    "transformation": {
+      "type": "object",
+      "allOf": [{ "$ref": "#/definitions/object_usage" }],
+      "properties": {
+        "type": { "type": "string", "enum": ["Transformation"] },
+        "name": { "type": "string" },
+        "source_crs": { "$ref": "#/definitions/crs" },
+        "target_crs": { "$ref": "#/definitions/crs" },
+        "interpolation_crs": { "$ref": "#/definitions/crs" },
+        "method": { "$ref": "#/definitions/method" },
+        "parameters": {
+            "type": "array",
+            "items": { "$ref": "#/definitions/parameter_value" }
+        },
+        "accuracy": { "type": "string" },
+        "$schema" : {},
+        "scope": {},
+        "area": {},
+        "bbox": {},
+        "usages": {},
+        "remarks": {},
+        "id": {}, "ids": {}
+      },
+      "required" : [ "name", "source_crs", "target_crs", "method", "parameters" ],
+      "additionalProperties": false
+    },
+
+    "unit": {
+      "oneOf": [
+      {
+        "type": "string",
+        "enum": ["metre", "degree", "unity"]
+      },
+      {
+        "type": "object",
+        "properties": {
+          "type": { "type": "string",
+                    "enum": ["LinearUnit", "AngularUnit", "ScaleUnit",
+                             "TimeUnit", "ParametricUnit", "Unit"] },
+          "name": { "type": "string" },
+          "conversion_factor": { "type": "number" },
+          "id": { "$ref": "#/definitions/id" },
+          "ids": { "$ref": "#/definitions/ids" }
+         },
+         "required" : [ "type", "name" ],
+         "allOf": [
+            { "$ref": "#/definitions/id_ids_mutually_exclusive" }
+          ],
+         "additionalProperties": false
+      }
+      ]
+    },
+
+    "usages": {
+        "type": "array",
+        "items": {
+          "type": "object",
+          "properties": {
+            "scope": { "type": "string" },
+            "area": { "type": "string" },
+            "bbox": { "$ref": "#/definitions/bbox" }
+           },
+          "additionalProperties": false
+        }
+    },
+
+    "value_and_unit": {
+      "type": "object",
+      "properties": {
+        "value": { "type": "number" },
+        "unit": { "$ref": "#/definitions/unit" }
+      },
+      "required" : [ "value", "unit" ],
+      "additionalProperties": false
+    },
+
+    "value_in_degree_or_value_and_unit": {
+      "oneOf": [
+        { "type": "number" },
+        { "$ref": "#/definitions/value_and_unit" }
+      ]
+    },
+
+    "value_in_metre_or_value_and_unit": {
+      "oneOf": [
+        { "type": "number" },
+        { "$ref": "#/definitions/value_and_unit" }
+      ]
+    },
+
+    "vertical_crs": {
+      "type": "object",
+      "properties": {
+        "type": { "type": "string", "enum": ["VerticalCRS"] },
+        "name": { "type": "string" },
+        "datum": {
+            "oneOf": [
+                { "$ref": "#/definitions/vertical_reference_frame" },
+                { "$ref": "#/definitions/dynamic_vertical_reference_frame" }
+            ]
+        },
+        "datum_ensemble": { "$ref": "#/definitions/datum_ensemble" },
+        "coordinate_system": { "$ref": "#/definitions/coordinate_system" },
+        "geoid_model": {
+          "type": "object",
+          "properties": {
+            "name": { "type": "string" },
+            "interpolation_crs": { "$ref": "#/definitions/crs" },
+            "id": { "$ref": "#/definitions/id" }
+          },
+          "required" : [ "name" ],
+          "additionalProperties": false
+        },
+        "$schema" : {},
+        "scope": {},
+        "area": {},
+        "bbox": {},
+        "usages": {},
+        "remarks": {},
+        "id": {}, "ids": {}
+      },
+      "required" : [ "name"],
+      "description": "One and only one of datum and datum_ensemble must be provided",
+      "allOf": [
+        { "$ref": "#/definitions/object_usage" },
+        { "$ref": "#/definitions/one_and_only_one_of_datum_or_datum_ensemble" }
+      ],
+      "additionalProperties": false
+    },
+
+    "vertical_reference_frame": {
+      "type": "object",
+      "allOf": [{ "$ref": "#/definitions/object_usage" }],
+      "properties": {
+        "type": { "type": "string", "enum": ["VerticalReferenceFrame"] },
+        "name": { "type": "string" },
+        "anchor": { "type": "string" },
+        "$schema" : {},
+        "scope": {},
+        "area": {},
+        "bbox": {},
+        "usages": {},
+        "remarks": {},
+        "id": {}, "ids": {}
+      },
+      "required" : [ "name" ],
+      "additionalProperties": false
+    }
+
+  }
+}
diff --git a/src/iso19111/crs.cpp b/src/iso19111/crs.cpp
index be593878..598cedad 100644
--- a/src/iso19111/crs.cpp
+++ b/src/iso19111/crs.cpp
@@ -5528,13 +5528,6 @@ void BoundCRS::_exportToJSON(
 {
     auto writer = formatter->writer();
     const auto &l_name = nameStr();
-    if ((formatter->outputUsage(true) && !domains().empty()) ||
-        (formatter->outputId() && !identifiers().empty()) ||
-        !remarks().empty() ||
-        (!l_name.empty() && l_name != d->baseCRS()->nameStr())) {
-        // Only upgrades to v0.3 schema if needed
-        formatter->setSchema(io::JSONFormatter::PROJJSON_v0_3);
-    }
 
     auto objectContext(formatter->MakeObjectContext("BoundCRS", false));
 
diff --git a/src/iso19111/io.cpp b/src/iso19111/io.cpp
index 5d7e951e..d3928a86 100644
--- a/src/iso19111/io.cpp
+++ b/src/iso19111/io.cpp
@@ -35,6 +35,7 @@
 #include <cctype>
 #include <cmath>
 #include <cstring>
+#include <limits>
 #include <list>
 #include <locale>
 #include <map>
@@ -106,14 +107,10 @@ NS_PROJ_START
 namespace io {
 
 //! @cond Doxygen_Suppress
-const char *JSONFormatter::PROJJSON_v0_2 =
-    "https://proj.org/schemas/v0.2/projjson.schema.json";
+const char *JSONFormatter::PROJJSON_v0_4 =
+    "https://proj.org/schemas/v0.4/projjson.schema.json";
 
-const char *JSONFormatter::PROJJSON_v0_3 =
-    "https://proj.org/schemas/v0.3/projjson.schema.json";
-
-// v0.2 is our base version. We only upgrade to 0.3 for usage node in BoundCRS
-#define PROJJSON_DEFAULT_VERSION JSONFormatter::PROJJSON_v0_2
+#define PROJJSON_DEFAULT_VERSION JSONFormatter::PROJJSON_v0_4
 
 //! @endcond
 
@@ -5398,6 +5395,36 @@ IdentifierNNPtr JSONParser::buildId(const json &j, bool removeInverseOf) {
     } else {
         throw ParsingException("Unexpected type for value of \"code\"");
     }
+
+    if (j.contains("version")) {
+        auto versionJ = j["version"];
+        std::string version;
+        if (versionJ.is_string()) {
+            version = versionJ.get<std::string>();
+        } else if (versionJ.is_number()) {
+            const double dblVersion = versionJ.get<double>();
+            if (dblVersion >= std::numeric_limits<int>::min() &&
+                dblVersion <= std::numeric_limits<int>::max() &&
+                static_cast<int>(dblVersion) == dblVersion) {
+                version = internal::toString(static_cast<int>(dblVersion));
+            } else {
+                version = internal::toString(dblVersion);
+            }
+        } else {
+            throw ParsingException("Unexpected type for value of \"version\"");
+        }
+        propertiesId.set(Identifier::VERSION_KEY, version);
+    }
+
+    if (j.contains("authority_citation")) {
+        propertiesId.set(Identifier::AUTHORITY_KEY,
+                         getString(j, "authority_citation"));
+    }
+
+    if (j.contains("uri")) {
+        propertiesId.set(Identifier::URI_KEY, getString(j, "uri"));
+    }
+
     return Identifier::create(code, propertiesId);
 }
 
@@ -10709,10 +10736,7 @@ JSONFormatter &JSONFormatter::setIndentationWidth(int width) noexcept {
  * If set to empty string, it will not be written.
  */
 JSONFormatter &JSONFormatter::setSchema(const std::string &schema) noexcept {
-    // Upgrade only to v0.3 if the default was v0.2
-    if (schema != PROJJSON_v0_3 || d->schema_ == PROJJSON_v0_2) {
-        d->schema_ = schema;
-    }
+    d->schema_ = schema;
     return *this;
 }
 
diff --git a/src/iso19111/metadata.cpp b/src/iso19111/metadata.cpp
index e8ce37c6..fc1b103f 100644
--- a/src/iso19111/metadata.cpp
+++ b/src/iso19111/metadata.cpp
@@ -41,6 +41,7 @@
 #include "proj_json_streaming_writer.hpp"
 
 #include <algorithm>
+#include <limits>
 #include <memory>
 #include <string>
 #include <vector>
@@ -1114,6 +1115,31 @@ void Identifier::_exportToJSON(JSONFormatter *formatter) const {
         } catch (const std::exception &) {
             writer->Add(l_code);
         }
+
+        if (version().has_value()) {
+            const auto l_version = *(version());
+            writer->AddObjKey("version");
+            try {
+                const double dblVersion = c_locale_stod(l_version);
+                if (dblVersion >= std::numeric_limits<int>::min() &&
+                    dblVersion <= std::numeric_limits<int>::max() &&
+                    static_cast<int>(dblVersion) == dblVersion) {
+                    writer->Add(static_cast<int>(dblVersion));
+                } else {
+                    writer->Add(dblVersion);
+                }
+            } catch (const std::exception &) {
+                writer->Add(l_version);
+            }
+        }
+        if (authority().has_value() && *(authority()->title()) != l_codeSpace) {
+            writer->AddObjKey("authority_citation");
+            writer->Add(*(authority()->title()));
+        }
+        if (uri().has_value()) {
+            writer->AddObjKey("uri");
+            writer->Add(*(uri()));
+        }
     }
 }
 
diff --git a/test/cli/testprojinfo_out.dist b/test/cli/testprojinfo_out.dist
index 6c3a37c4..2405462d 100644
--- a/test/cli/testprojinfo_out.dist
+++ b/test/cli/testprojinfo_out.dist
@@ -160,7 +160,7 @@ GEOGCS["GCS_WGS_1984",DATUM["D_WGS_1984",SPHEROID["WGS_1984",6378137.0,298.25722
 
 PROJJSON:
 {
-  "$schema": "https://proj.org/schemas/v0.2/projjson.schema.json",
+  "$schema": "https://proj.org/schemas/v0.4/projjson.schema.json",
   "type": "GeographicCRS",
   "name": "WGS 84",
   "datum_ensemble": {
diff --git a/test/unit/test_c_api.cpp b/test/unit/test_c_api.cpp
index 721c54d5..600f47ff 100644
--- a/test/unit/test_c_api.cpp
+++ b/test/unit/test_c_api.cpp
@@ -4288,7 +4288,7 @@ TEST_F(CApi, proj_as_projjson) {
         EXPECT_EQ(std::string(projjson),
                   "{\n"
                   "  \"$schema\": "
-                  "\"https://proj.org/schemas/v0.2/projjson.schema.json\",\n"
+                  "\"https://proj.org/schemas/v0.4/projjson.schema.json\",\n"
                   "  \"type\": \"Ellipsoid\",\n"
                   "  \"name\": \"WGS 84\",\n"
                   "  \"semi_major_axis\": 6378137,\n"
diff --git a/test/unit/test_io.cpp b/test/unit/test_io.cpp
index 791a8b9e..a4fb5f6e 100644
--- a/test/unit/test_io.cpp
+++ b/test/unit/test_io.cpp
@@ -12035,12 +12035,9 @@ TEST(json_import, compound_crs) {
 // ---------------------------------------------------------------------------
 
 TEST(json_import, bound_crs) {
-    // Explicitly check that the version is v0.2 in that circumstance. Might
-    // require adjustments in the future.
     auto json =
         "{\n"
-        "  \"$schema\": "
-        "\"https://proj.org/schemas/v0.2/projjson.schema.json\",\n"
+        "  \"$schema\": \"foo\",\n"
         "  \"type\": \"BoundCRS\",\n"
         "  \"source_crs\": {\n"
         "    \"type\": \"GeographicCRS\",\n"
@@ -12134,18 +12131,17 @@ TEST(json_import, bound_crs) {
     auto obj = createFromUserInput(json, nullptr);
     auto boundCRS = nn_dynamic_pointer_cast<BoundCRS>(obj);
     ASSERT_TRUE(boundCRS != nullptr);
-    EXPECT_EQ(boundCRS->exportToJSON(JSONFormatter::create().get()), json);
+    EXPECT_EQ(
+        boundCRS->exportToJSON(&(JSONFormatter::create()->setSchema("foo"))),
+        json);
 }
 
 // ---------------------------------------------------------------------------
 
 TEST(json_import, bound_crs_with_name_and_usage) {
-    // Explicitly check that the version is v0.3 in that circumstance. Might
-    // require adjustments in the future.
     auto json =
         "{\n"
-        "  \"$schema\": "
-        "\"https://proj.org/schemas/v0.3/projjson.schema.json\",\n"
+        "  \"$schema\": \"foo\",\n"
         "  \"type\": \"BoundCRS\",\n"
         "  \"name\": \"my bound crs\",\n"
         "  \"source_crs\": {\n"
@@ -12252,7 +12248,9 @@ TEST(json_import, bound_crs_with_name_and_usage) {
     auto obj = createFromUserInput(json, nullptr);
     auto boundCRS = nn_dynamic_pointer_cast<BoundCRS>(obj);
     ASSERT_TRUE(boundCRS != nullptr);
-    EXPECT_EQ(boundCRS->exportToJSON(JSONFormatter::create().get()), json);
+    EXPECT_EQ(
+        boundCRS->exportToJSON(&(JSONFormatter::create()->setSchema("foo"))),
+        json);
 }
 
 // ---------------------------------------------------------------------------
@@ -13919,6 +13917,78 @@ TEST(json_import, derived_temporal_crs) {
 
 // ---------------------------------------------------------------------------
 
+TEST(json_import, id) {
+    auto json = "{\n"
+                "  \"$schema\": \"foo\",\n"
+                "  \"type\": \"Ellipsoid\",\n"
+                "  \"name\": \"WGS 84\",\n"
+                "  \"semi_major_axis\": 6378137,\n"
+                "  \"inverse_flattening\": 298.257223563,\n"
+                "  \"id\": {\n"
+                "    \"authority\": \"EPSG\",\n"
+                "    \"code\": 6326,\n"
+                "    \"version\": 1,\n"
+                "    \"authority_citation\": \"my citation\",\n"
+                "    \"uri\": \"my uri\"\n"
+                "  }\n"
+                "}";
+    auto obj = createFromUserInput(json, nullptr);
+    auto ellps = nn_dynamic_pointer_cast<Ellipsoid>(obj);
+    ASSERT_TRUE(ellps != nullptr);
+    EXPECT_EQ(ellps->exportToJSON(&(JSONFormatter::create()->setSchema("foo"))),
+              json);
+}
+
+// ---------------------------------------------------------------------------
+
+TEST(json_import, id_code_string_version_string) {
+    auto json = "{\n"
+                "  \"$schema\": \"foo\",\n"
+                "  \"type\": \"Ellipsoid\",\n"
+                "  \"name\": \"WGS 84\",\n"
+                "  \"semi_major_axis\": 6378137,\n"
+                "  \"inverse_flattening\": 298.257223563,\n"
+                "  \"id\": {\n"
+                "    \"authority\": \"EPSG\",\n"
+                "    \"code\": \"abc\",\n"
+                "    \"version\": \"def\",\n"
+                "    \"authority_citation\": \"my citation\",\n"
+                "    \"uri\": \"my uri\"\n"
+                "  }\n"
+                "}";
+    auto obj = createFromUserInput(json, nullptr);
+    auto ellps = nn_dynamic_pointer_cast<Ellipsoid>(obj);
+    ASSERT_TRUE(ellps != nullptr);
+    EXPECT_EQ(ellps->exportToJSON(&(JSONFormatter::create()->setSchema("foo"))),
+              json);
+}
+
+// ---------------------------------------------------------------------------
+
+TEST(json_import, id_code_string_version_double) {
+    auto json = "{\n"
+                "  \"$schema\": \"foo\",\n"
+                "  \"type\": \"Ellipsoid\",\n"
+                "  \"name\": \"WGS 84\",\n"
+                "  \"semi_major_axis\": 6378137,\n"
+                "  \"inverse_flattening\": 298.257223563,\n"
+                "  \"id\": {\n"
+                "    \"authority\": \"EPSG\",\n"
+                "    \"code\": \"abc\",\n"
+                "    \"version\": 9.8,\n"
+                "    \"authority_citation\": \"my citation\",\n"
+                "    \"uri\": \"my uri\"\n"
+                "  }\n"
+                "}";
+    auto obj = createFromUserInput(json, nullptr);
+    auto ellps = nn_dynamic_pointer_cast<Ellipsoid>(obj);
+    ASSERT_TRUE(ellps != nullptr);
+    EXPECT_EQ(ellps->exportToJSON(&(JSONFormatter::create()->setSchema("foo"))),
+              json);
+}
+
+// ---------------------------------------------------------------------------
+
 TEST(json_import, multiple_ids) {
     auto json = "{\n"
                 "  \"$schema\": \"foo\",\n"