Ruling 468. There are six categories of women in menstruation:

1. a woman with a habit of time and duration: this is a woman who on two consecutive months starts her period at a fixed time, and the number of days on which she has her period is the same in each of the two months. For example, in two consecutive months she experiences bleeding from the first of the month until the seventh;

2. a woman with a habit of time: this is a woman who on two consecutive months starts her period at a fixed time but the number of days on which she has her period is not the same in each of the two months. For example, in two consecutive months she experiences bleeding on the first of the month, but in the first month her bleeding stops on the seventh day and in the second month it stops on the eighth day;

3. a woman with a habit of duration: this is a woman who has her period for the same number of days on two consecutive months but the time when her bleeding starts in each of the two months is not the same. For example, in the first month she experiences bleeding from the fifth to the tenth of the month and in the second month from the twelfth to the seventeenth;

4. a woman with a disordered habit (muḍṭaribah): this is a woman who, for several months, experiences a period but does not have a fixed habit with regard to this [neither of time nor duration], or her habit has been disturbed and she has not yet formed a new habit;

5. a menarcheal woman (mubtadiʾah): this is a woman who experiences bleeding for the first time;

6. a forgetful woman (nāsiyah): this is a woman who has forgotten the habit of her period.

Specific rules apply to each of these categories, which will be discussed in the following rulings.