NPCL is the Networked Planet Constraint Language, a simple model for defining constraints on a topic map such as the topics that can be used as topic, association, role and occurrence types; what occurrence types a topic type allows, how topics can be combined in associations and so on. You can read more about NPCL here.

An NPCL schema can be specified as an XML file or as topics and associations in a topic map. When specified in a topic map, there are a few predefined topics that are required. Normally the Networked Planet Topic Map Editor application will generate these predefined topics for you, but occassionally you will want to bootstrap an application without having to use the Topic Map Editor. The NPCL Base Topic Map XTM file provides these predefined topics in a form that can be imported into a TMCore database using the tmimport command line.

Download the NPCL Base Topic Map.