提供NZS 1170.5:2004中各项规定的背景，提出可能满足本标准意图的方法，并在适当情况下描述本标准与之前版本之间的差异。参考文献供进一步阅读，并在评注每一节末尾给出。

Provides background to the various provisions in NZS 1170.5:2004, suggests approaches that may satisfy the intent of the Standard and, if appropriate, describes differences between this and previous editions of the Standard. References are provided for further reading and these are given at the end of each section of the Commentary.