## The value of a member named "crs" must be an object.  This object must have at least two named members: "type" and "properties".  The value of the member named "type" must be a string.  The value of the member named "properties" must be an object.  This specification defines no further requirements for the structure of these objects.  Instead, a convention is offered.

## The value of a member named "crs" must be an object.  This object must have at least two named members: "type" and "properties".  The value of the member named "type" must be a string.  The value of the member named "properties" must be an object.  This specification defines no further requirements for the structure of these objects.  Instead, a convention is offered.

### To use EPSG codes to describe coordinate reference system, the "crs" member should have the following structure: <code>"crs": {"type": "EPSG", "properties": {"code": 4267}}</code>. "crs", "type", and "properties" must be lower case. When used as a value, "EPSG" must be upper case.

### To use EPSG codes to describe coordinate reference system, the "crs" member should have the following structure: <code>"crs": {"type": "EPSG", "properties": {"code": 4267}}</code>. "crs", "type", and "properties" must be lower case. When used as a value, "EPSG" must be upper case.