Those who maintain any of the seven kinds
Of individual liberation vow
Have the ideal [prerequisite] for
The Bodhisattva vow, not others
The Tathagatha spoke of seven kinds
Of individual liberation vow.
The best of these is glorious pure conduct,
Said to be the vow of a fully ordained person.
Before one can take the bodhisattva vow, one must first take refuge, which is the ceremony where one formally declares oneself a Buddhist. And one must also take the pratinmoksha vows along with refuge. Pratimoksha is Sanskrit for individual liberation. In the Pratimoksha vow one commits to a code of conduct. There are three levels of vows: lay, novice ordained, and fully ordained. Three times the two sexes makes six. And the seventh? Nuns have an extra level of vows between novice and fully ordained. (i think. I don't have my copy of Jewel Ornament.) There are five lay pratimkosha vows (no killing, stealing, lying, sexual misconduct, or intoxicants), ten novice vows, and approximately 250 vows for the fully ordained. Fully ordained nuns have the most vows, they are the pratimoksha champs! The point of taking vows is to lead a harmless and restrained life. In this way the pratimoksha vows serve as the basis of bodhisatta vows, as they have the same intent. And the vows of the fully ordained serve as the best basis for the bodhisattva vow, although any will do.