There are over 70 defined terms (e.g. There are over fifty defined terms (e.g. abnormal course condition, general area, etc.) and these form the foundation around which the Rules are written. A good knowledge of the defined terms (which are italicised throughout the book and contained in one section near the back of the book) is very important to the correct application of the Rules.
Abnormal Course Condition
Any of these four defined conditions:
To include the 70 definitions would make this page impossibly long, so included is a link to the R&A Web Based Definitions