The bhikkhunī-vibhaṅga (“the analysis of the nuns’ rules”) contains the monastic code for nuns, the bhikkhunī-pātimokkha, embedded in explanatory material. The bhikkhunī-vibhaṅga is divided into seven chapters, each dealing with a separate class of rules, grouped according to the offense incurred in breaking them, with the exception of the adhikaraṇasamathadhamma (“the principles for resolving legal issues”), which are principles to be applied rather than rules in the strict sense.
Each rule together with its explanatory material forms an independent unit, a sub-chapter. These units begin with one or more origin stories, which tell the circumstances that led the Buddha to lay down a particular rule. The rule is then stated, followed by a word commentary that analyzes every significant word contained in the rule. After the word commentary follows a permutation series in which a variety of different scenarios are evaluated and offenses assigned as appropriate. At the end comes a non-offense clause, stating important exceptions to the rule, sometimes followed by individual case studies, in which the Buddha decides the offense incurred in ambiguous cases.
The rules in this category are known in Pali as pārājika. The exact meaning of the Pali word is disputed, but there is no doubt that it refers to expulsion from the monastic Order. There are eight such rules for the nuns, four of which are shared with the monks. Anyone who breaches any of these rules immediately loses her status as a nun. She is expelled from the Order and ineligible for re-ordination for the rest of her life. The pārājikas, together with the next category of rules, the saṅghādisesas, are collectively known as serious offenses, garukāpatti. These rules are the most fundamental ones for the proper living of the monastic life.
The rules in this category are known in Pali as saṅghādisesa. The exact meaning of the Pali word is disputed, but according to the commentary it means that the Order (saṅgha) is required at the beginning (ādi) and for the rest (sesa) of the procedure. There are seventeen such rules for the nuns, seven of which are shared with the monks. Anyone who breaches any of these rules is to be suspended from the monastic Order. The offender must go through a process of rehabilitation called mānatta, “trial period,” lasting half a month. During the rehabilitation period the offending nun loses her normal status and is required to follow a number of special provisions, such as not staying in the same room as a regular nun and not going anywhere by herself. When the rehabilitation process has been completed, an Order of twenty nuns is required to formally rehabilitate the offender. She then regains her full status as a nun. The saṅghādisesas and the pārājikas are collectively known as serious offenses, garukāpatti. After the pārājikas, the saṅghādisesas are the most fundamental rules for the proper living of the monastic life.
The rules in this category are known in Pali as nissaggiya pācittiya, “entailing relinquishment and confession.” There are thirty such rules for the nuns, the same number as for the monks, although only eighteen are held in common. These rules, together with the remaining rules of the monastic code, are classed as light offenses, lahukāpatti. For light offenses there is no penalty apart from confession. For the nissaggiya pācittiyas, however, any item involved in the committing of an offense must be relinquished. Once the offense has been confessed, the item is, with a few exceptions, returned to the offender. The purpose of this process is perhaps to remind the offender to treat the item in the appropriately manner.