The Open GIS Consortium, Inc. (OGC) has released a Request for Comments (RFC) on the OpenGIS® Styled Layer Descriptor (SLD) Implementation Specification. The OGC membership is considering adoption of this draft specification. The SLD specification defines an extension to the Web Map Server Specification to allow user-defined symbolization of feature data independent of the geographic data or the brand of geoprocessing technology used. OGC members CubeWerx Inc., (Editor, Canada), Syncline (US), and Ionic Software s.a. (Belgium) submitted the SLD specification as a Request for Comment. Industry comments are invited through June 6, 2002.
Because maps are a form of graphic representation, those who use them need a way to consistently document and control the map display for effective presentation, no matter the source of the data. The SLD specification addresses this need and also supports the ability for geographic data to be stored and processed independently of symbology.
The RFC for the OpenGIS Styled Layer Descriptor Specification documents a styling language that allows software applications and end users greater control over symbology. The proposed language, called the Styled Layer Descriptor, is an XML encoding that can be used to portray the output of Web Map Servers (servers for vector, raster or matrix data), Web Feature Servers (servers for vector feature data) and Web Coverage Servers (servers for raster or matrix data)
that implement OpenGIS® Specifications. The SLD language enables a wide range of capabilities, from simple rendering such as colouring all of the water in a layer blue, to more complex renderings that determine symbology based on a feature’s attribute or user preference. In this case, wider rivers might be drawn proportionately thicker than thinner streams.
The RFC is available for review and comment at https://www.opengis.org/techno/rfc14info.htm.