Using sections and modules to organize and reference content.
Modules
The Module Doctype's main and only purpose is to define content to be used for transclusion. Typically it has a section for the content to be transcluded. All other sections and all properties are used to categorize the module and add references to related information. The Module Doctype also provides a section that lists all documents that transclude content from the document instance.
As with the Section Doctype, transclusions are easy with macros from the projectdoc Toolbox.
Topics and Tours
The Topic Doctype is used to document a topic. In contrast to the Section Doctype the topic is a document on its own. In contrast to the Module Doctype the topic's main purpose is not designed primarily for reuse. Use the Tour Doctype to organize topics in a single document.
Resources
More information on modularization.