- Modules
- UG-2.2.1- Rulebook Volumes are subdivided into Modules, arranged in groups according to their subject matter, underneath the headings listed in Paragraph UG-2.1.3 above. 
- UG-2.2.2- Each Module in a Volume is referenced using a two-or three-letter code, which is usually a contraction or abbreviation of its title. These codes are used for cross-referencing within the text. Amended: October 2012
