Subject: [Geojson] Appendix B. Changes

From: Sean Gillies <[email-masked]>
Date: Mon, 29 Feb 2016 11:19:07 -0700

I've extracted appendix B from the latest build of PR #160.

  https://circleci.com/gh/geojson/draft-geojson/54#artifacts

Please let me know if I've missed anything or have written something
inaccurately.

B.1.  Normative changes

   o  Coordinate reference systems other than the default are NOT
      RECOMMENDED (see Section 4).

   o  In the absence of elevation values, applications sensitive to
      height or depth SHOULD interpret positions as being at local
      ground or sea level (see Section 4).

   o  Implementations SHOULD NOT extend position arrays beyond 3
      elements (see Section 3.1.1).

   o  A line between two positions is a straight Cartesian line (see
      Section 3.1.1).

   o  The values of a "bbox" array are "[%west%, %south%, %east%,
      %north%]", not [%minx%, %miny%, %maxx%, %maxy%]` (see Section 5).

   o  Extensions MAY be used, but MUST NOT change the the semantics of
      GeoJSON members and types (see Section 6).

   o  GeoJSON objects MUST NOT contain the defining members of other
      types (see Section 6.3).

   o  The media type for GeoJSON is application/geo+json.

B.2.  Informative changes

   o  The definition of a GeoJSON text has been added.

   o  Rules for mapping 'geo' URIs have been added.

   o  A recommendation of the I-JSON [RFC7493] constraints has been
      added.

   o  Implementers are cautioned about the effect of excessive
      coordinate precision on interoperability.

   o  Right-hand rule orientation of polygon rings (counter-clockwise
      external rings, clockwise internal rings) is recommended to
      improve interoperability.

   o  Interoperability concerns of geometry collections are noted.
      These objects should be used sparingly (see Section 10.5).

-- 
Sean Gillies