garu-dhamma (Pāli; Skt., guru-dharma). The eight additional ‘weighty rules’ that the Buddha imposed as a condition of allowing women to be ordained as nuns. The intention behind the rules is commonly said to be to place nuns in an inferior position to monks, but a recent alternative explanation suggests they are intended more as a safeguard for women living in vulnerable situations. The additional rules are listed in the Cullavagga as follows. (1) A nun must always show deference to monks, for example by bowing even to the most junior monk. (2) A nun should not spend the rain-retreat (vassa) in a place where there are no monks. (3) The monthly poṣadha ceremony should be led by a monk. (4) At the end of the rain-retreat a nun must appear before the assemblies of monks and nuns to report on any actual or suspected breaches of the disciplinary rules. (5) If a nun commits a serious offence she must undergo expiation before both assemblies. (6) After her two-year period of training as a novice (śrāmaṇerī) is complete, a nun must be ordained by both assemblies. (7) A nun must never offend or insult a monk. (8) Nuns must never admonish a monk, but monks may admonish a nun.

A Dictionary of Buddhism, Oxford University Press, 2003, 2004 (which is available in electronic version from answer.com)