projectdoc documents are defined by properties and sections. A section is typically defined by the Section Macro. Such sections can be referenced, but require the fragment identifier to do so. In order to modularize a document, sections can be added by the use of the Section Doctype and transcluded by a transclusion macro – either one-by-one using the Transclusion Macro or the Transclude Documents Macro. The section documents are typically stored as child documents to the transcluding document. Therefore the Transclude Documents Macro allows to create a document divided into section documents easily. In addition to that these section documents ca be referenced more easily.

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.

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.