Khariji (plural khawarij): Those who separated from 'Ali (a.
Khariji (plural khawarij): Those who separated from 'Ali (a.s.) after the arbitration, claiming that 'Ali (a.s.) had become, God forbid, kafir. Khawarij are kuffar in the eyes of shari'ah. Nasibi (plural Nawasib): anyone who hates any of the twelve Imams or insult him. Nasibi too is kafir. ' Anyone who abuses, or uses foul language, about the Prophet (s.a.w.a.), Bibi Fatimah, or any of the Twelve Imams is kafir.
There are certain rules governing all the above-mentioned kuffar: (1) A mushrik is najis (unclean). As for the people of the Book (i.e. the Jews and the Christians) opinions differ. The reader should consult the 'amaliyyah of his mujtahid. (2)A non-Muslim man is not allowed to marry a Muslim woman, a non-Muslim woman is not allowed to marry a Muslim man. The only exception is a Christian woman or Jewess marrying a Muslim man in Mut'ah form.
(3) A non-Muslim cannot inherit from a Muslim - no matter how close their relationship may be. (4) A non-Muslim cannot possess a Muslim Slave. (5) An animal slaughtered by a non-Muslim is treated as a dead animal; it is not lawful to eat from that animal. (6) Meat, fat, hide and skin, in possession of a non-Muslim are najis, unless one knows that he has got it from a Muslim. (7) It is not wajib on Muslims to conduct funeral rites of a non-Muslim.
(8) There is a special rule about the last mentioned category of kafir, i.e. the one who abuses or uses foul language concerning any of the 14 Ma'sumeen. It is wajib (compulsory, obligatory) on any Muslim who can do so, to kill him - without any need of referring the case to the qadi of shari'ah. There is a particular kind of kafir who is called Murtadd (apostate), i.e. a person who accepted Islam and then renounced it. The position of Murtadd is worse than an original kafir.
Some important rules about murtadd are given here. Murtadd is of two kinds: Murtadd Fitri and Murtadd Milli. Murtadd Fitri: A person both (or at least one) of whose parents were Muslims at the time of his conception, and then, he/she, on attaining majority, renounces Islam by his own free will. The rules about Murtadd Fitri differ according to the sex of the offender, i.e. there are different rules for males and females.
A male Murtadd Fitri is najis; his wife becomes haram, for him, and she will observe 'iddah of death; even during his life he loses all rights in his property - after repaying his debts the residue will be distributed among his Muslim heirs.