After the Parinibbana (Final Passing) of the Buddha, the Buddhist monastic order developed into a primarily cenobitic or communal movement. The practice of living communally during the rainy vassa season, prescribed by the Buddha, gradually grew to encompass a settled monastic life centered on life in a community of practitioners. Most of the modern disciplinary rules followed by bhikkhus and bhikkhunis — as encoded in the Patimokkha — relate to such an existence, prescribing in great detail proper methods for living and relating in a community of bhikkhus or bhikkhunis. The number of rules observed varies with the order; Theravada bhikkhus follow around 227 rules, the Vinaya. There are a larger number of rules specified for bhikkhunis (nuns).