The OGC requests comment on the candidate standard Geographic Information – Well Known Text for coordinate reference systems


Wednesday, 2 October 2013 UTC

2 October 2013 - The Open Geospatial Consortium (OGC®) is seeking comments on the candidate OGC standard, "Geographic Information – Well Known Text (WKT) for coordinate reference systems."

OGC Well Known Text offers a compact machine-readable and human-readable representation of geometric objects. WKT can also be used for succinctly describing the critical elements of coordinate reference system (CRS) definitions. 

WKT is described in the OGC standard “Geographic information – Simple feature access – Part 1: Common architecture” (also International Standard ISO 19125-1:2004). The WKT representation of coordinate reference systems was subsequently extended in other OGC standards. As a result, there are inconsistencies in how WKT CRS is expressed in various OGC and ISO standards.

This draft standard provides an updated version of WKT representation of coordinate reference systems that follows the provisions of OGC Abstract Specification Topic 2 (ISO 19111:2007) Spatial Referencing by Coordinates. The draft extends earlier WKT to allow for the description of coordinate transformations. This draft standard defines the structure and content of well known text strings. It does not prescribe how implementations should read or write these strings.

Comments are due by 1 November 2013, but we encourage those interested to comment by 26th October. This draft has been submitted by the OGC to ISO TC211 as a Committee Draft for ballot as a Draft International Standard (document N3596). Comments received as part of the OGC RFC by 26th October will be fed into the ISO ballot. 

All OGC standards are free and publicly available. Download the candidate OGC WKT CRS draft standard at  A proof of concept evaluation package may be downloaded at

The OGC is an international consortium of more than 475 companies, government agencies, research organizations, and universities participating in a consensus process to develop publicly available geospatial standards. OGC Standards support interoperable solutions that "geo-enable" the Web, wireless and location-based services, and mainstream IT. OGC Standards empower technology developers to make geospatial information and services accessible and useful with any application that needs to be geospatially enabled. Visit the OGC website at