OGC Seeks Public Comment on Proposed Community Standard Work Item Justification for Extended Well-Known Binary

November 13, 2025

The Open Geospatial Consortium (OGC) seeks public comment on the proposed Community Standard Work Item Justification for Extended Well-Known Binary (EWKB), an extension of OGC’s Well-Known Binary (WKB) format that adds support for additional dimensions and spatial reference identifiers.

The Well-Known Binary (WKB) representation of geometry was defined by OGC in 2004 as part of the Simple Features Access Part 1 Common Architecture standard. It is used to encode two-dimensional geometries and does not cater for the storage of a Spatial Reference Identifier (SRID).

As GeoSPARQL 1.3 is an update of the standard to support 3D use cases, and an SRS is a required component of the encoding, WKB does not explicitly meet the needs of a binary encoding for GeoSPARQL.

The Extended Well-Known Binary (EWKB) is an open specification designed to extend OGC’s WKB encoding to address the following shortcomings:

• WKB made no allowance for more than an X and Y coordinate, such as the Z and M coordinates that are common in GIS applications.
• WKB made no allowance for embedding a Spatial Reference Identifier (SRID), which made it unusable as a database import/export format.

Extended WKB, defined by the open source community, recognizes these shortcomings of the standard and extends it through backwards-compatible additions of extra dimensions (e.g., Z and M that are commonly used by GIS applications) and an SRID. It is broadly used in databases and libraries that extend the OGC Simple Features specification.

All content used for this document was sourced from the following webpages:

• https://github.com/postgis/postgis/blob/master/doc/ZMSgeoms.txt 
• https://libgeos.org/specifications/wkb/#extended-wkb

As such, the OGC does not assert any intellectual property rights over this standard.

This proposed OGC Community Standard is an outcome of the development of GeoSPARQL 1.3, created to satisfy the requirement of a normative reference for a binary encoding.

To Comment

The proposed Extended Well-Known Binary (EWKB) Community Standard Work Item Justification is available for review and comment for a period of 30 days. Comments are due by December 13, 2025.

Documents for review:

• https://portal.ogc.org/files/?artifact_id=111657&version=1
• https://portal.ogc.org/files/?artifact_id=111658&version=1

Comments can be submitted to a dedicated email reflector for a period ending on the “Close request date” listed above. Comments received will be consolidated and reviewed by OGC members for incorporation into the document. Please submit your comments via this email address, using this Comments Template for the message body.

About OGC

The Open Geospatial Consortium (OGC) is a membership organization dedicated to using the power of geography and technology to solve problems faced by people and the planet. OGC unlocks value and opportunity for its members through Standards, Innovation, and Collaboration. Our membership represents a diverse and active global community drawn from government, industry, academia, international development agencies, research & scientific organizations, civil society, and advocates.

Visit ogc.org for more information about our work.