principles of Jewish law in a manner leaving no room for its integration into the system. From time to time the halakhic scholars exercised such control in order to contain or discredit entirely a particular custom. Present day The acute displacement brought about by World War II and the Holocaust, and the large-scale immigration to the United States, various European countries, and especially the State of Israel, have led to a "liberal mixing" of various minhagim, and arguably the falling into disuse of certain customs. In addition, the baal teshuva movement has created a large group who have no clear tradition from their parents. In response to these phenomena, certain scholars have focused on the minhagim, and attempts have been made to revive minhagim that have fallen into disuse. Nusach Nusach (properly nósach) primarily means "text" or "version", the correct wording of a religious text. Thus, the nusach tefillah is the text of the prayers, either generally or as used by a particular community. In common use nusach has come to signify the entire liturgical tradition of the community, including the musical rendition. It is narrower than minhag, which can refer to custom in any field, not necessarily that of communal prayer. Both nusach and minhag can thus be used for liturgic rite or liturgic tradition though sometimes a nusach appears to be a subdivision of a minhag or vice versa; see different Jewish rites and popular siddurim under Siddur. In general one must pray according to one's "nusach of origin" unless one has formally joined a different community and accepted its minhag. (Perisha rules that if one abandons a nusach that has been accepted universally by the wider Jewish community, his prayer is disqualified and must be repeated using the accepted nusach: Arba'ah Turim, Orach Chayim, 120 ad loc). The main segments of traditional Judaism, as differentiated by nusach (broadly and narrowly), are these: Nusach Ashkenaz: the general Ashkenazi rite of non-Chasidim. Can be subdivided into: Minhag Ashkenaz (German rite) Minhag Polin/Lita (Polish/Lithuanian/Prague rite) Nusach Sefard or Nusach Ari (Ashkenazi Chasidic rite, heavily influenced by the teachings of Sephardi Kabbalists) Minhag Sefaradi: in general refers to the various Sephardi liturgies, but also to obligation/permissibility of Kabbalistic elements within the rite. Versions of this are: The Spanish and Portuguese Jewish Rite Nusach Morocco (Moroccan rite: there are differences between the Spanish-Moroccan and the Arab-Moroccan customs) Nusach HaChida (The Chida'''s rite,