message: Alainr nextversion update
diff: @@ -1637,3 +1637,54 @@ To use any other external storage set [IModelHostConfiguration.tileCacheService]
  // With this:
  config.tileCacheService = new CustomCloudStorageService();
  ```
  +
  +## Coordinate Conversion between iModel GeographicCRS and any other GeographicCRS
  +
  +Coordinate conversions is now possible between the iModel Geographic Coordinate Reference System and any other Geographic Coordinate Reference System.
  +Prior to this version, coordinate conversions were limited to those between the iModel Geographic Coordinate Reference System and latitude/longitude of a specified datum, usually WGS84.
  +
  +To use, in the backend create either a [IModelCoordinatesRequestProps]($common) or a [GeoCoordinatesRequestProps]($common) depending on the direction coordinates are to be converted. Set the [IModelCoordinatesRequestProps.source]($common) or the [GeoCoordinatesRequestProps.target]($common) property to a string containing either the name of a datum (typically WGS84) or an empty string to specify the iModel Geographic CRS native datum or a stringified version of a [GeographicCRSProps]($common) containing the definition of the source or target of the coordinate conversion. The request can be added coordinates to be converted and fed in methods iModel.getGeoCoordinatesFromIModelCoordinates or iModel.getIModelCoordinatesFromGeoCoordinates.
  +
  +Specification of the GeographicCRS can be complete or incomplete. Although fully-defined custom Geographic CRS are supported, most of the time simply specifying the id or the epsg code of the GeographicCRS is sufficient.
  +
  +Here are examples of typical GeographicCRS:
  +
  +```ts
  +{ horizontalCRS: { id: "CA83-II" }, verticalCRS: { id: "NAVD88" } }
  +```
  +
  +or
  +
  +```ts
  +{ horizontalCRS: { epsg: 26942 }, verticalCRS: { id: "NAVD88" } },
  +```
  +
  +These identifiers refer to either the key-name of a Geographic CRS in the list of the dictionary or a known EPSG code.
  +
  +More complex Geographic CRS can also be used such as the following user-defined:
  +
  +```ts
  + {
  + horizontalCRS: {
  + id: "UserDef-On-NAD83/2011",
  + description: "User Defined",
  + datumId: "NAD83/2011",
  + unit: "Meter",
  + projection: {
  + method: "TransverseMercator",
  + centralMeridian: -1.5,
  + latitudeOfOrigin: 52.30,
  + scaleFactor: 1.0,
  + falseEasting: 198873.0046,
  + falseNorthing: 375064.3871,
  + },
  + },
  + verticalCRS: {
  + id: "GEOID",
  + },
  + }
  +```
  +
  +On the frontend the [GeoConverter]($frontend) class has been modified to accept either a string containing the datum or a [GeographicCRSProps]($common) of a similar format retaining cache capability as before for either format.
  +
  +**NOTE**: The [IModelCoordinatesRequestProps.source]($common) and the [GeoCoordinatesRequestProps.target]($common) were renamed from previous version that used the sourceDatum and targetDatum properties.
  