ISO 19144-1:2009/Cor 1:2012

Overview

This Technical Corrigendum (ISO 19144-1:2009/Cor 1:2012) updates Part 1 of the ISO 19144 series on classification system structure for geographic information. Prepared by ISO/TC 211, the corrigendum clarifies the relationship between legend classes and feature types by specifying how a CL_LegendClass instantiates the general GF_AttributeType metaclass defined in the General Feature Model (ISO 19109). It also explains implementation by reference to a catalogue of legend classes through CL_FeatureTypeReference, and confirms that feature attribute metadata may be associated with a legend class.

This clarification improves consistency in modeling classification systems, enhances metadata linkage, and supports more interoperable geographic datasets and systems.

Key Topics

• Legend class instantiation: The corrigendum states that a CL_LegendClass instantiates the GF_AttributeType metaclass from the General Feature Model (ISO 19109).
• Reference-based implementation: A legend class is implemented by referencing a catalogue of legend classes using CL_FeatureTypeReference, enabling re-use and standardized referencing across datasets.
• Attribute metadata association: Feature attribute metadata can be attached to a legend class, supporting clearer semantics and richer metadata descriptions for classification elements.
• Model clarification: Replacement of the paragraph in clause 5.5.4 and an updated Figure 8 provide a concise model of the relationship between legend classes and feature types.

These points are central to consistent application of classification systems in geographic information and support the integrity of feature-type to legend mappings.

Applications

The corrigendum has practical value for organizations and practitioners working with geographic classification systems:

• Cartography and map-production: Ensures legend classes used in maps are consistently instantiated and referenced, improving reproducibility of map symbology.
• Data catalogues and registries: Supports catalogue-based implementations where legend classes are centrally defined and referenced across datasets.
• Metadata management: Allows attribute-level metadata to be associated with legend classes, enhancing discoverability and interoperability of classification semantics.
• GIS software developers: Provides a clearer modeling approach for implementing classification structures that align with ISO 19109 and the General Feature Model.

Adopting the corrigendum's clarifications helps create interoperable classification systems, reduces ambiguity in feature-legend relationships, and streamlines metadata practices.

Related Standards

• ISO 19144-1:2009 - Classification systems - Part 1: Classification system structure (original publication)
• ISO 19144 (series) - Classification systems (other parts)
• ISO 19109 - Rules for application schema / General Feature Model (referenced metamodel)

This corrigendum was prepared by Technical Committee ISO/TC 211 (Geographic information/Geomatics) and should be used in conjunction with the referenced standards to ensure consistent implementation of classification system structures in geographic information systems.