Well-known text (
WKT) is a text
markup language for representing
vector geometry objects on a
map,
spatial reference systems of spatial objects and transformations between spatial reference systems. A
binary equivalent, known as
well-known binary (
WKB), is used to transfer and store the same information on databases, such as
PostGIS,
Microsoft SQL Server and
DB2. The formats were originally defined by the
Open Geospatial Consortium (OGC) and described in their
Simple Feature Access and Coordinate Transformation Service specifications. The current standard definition is in the ISO/IEC 13249-3:2011 standard, "Information technology -- Database languages -- SQL multimedia and application packages -- Part 3: Spatial" (SQL/MM).