Here is a quick translation of the communiqué released by the Diocese of Chur, which is also interesting in its reasoning:
For more than 35 years there have been in the Diocese of Chur two centres for faithful attached to the Extraordinary Form of the Roman Rite. There, pastoral care has been provided at a scale equivalent to many regular parishes, but without a corresponding regulation. The Bishop of Chur wants to end this unsatisfying long-time provisional arrangement and to establish canonical clarity. Therefore, on 22 February 2012 he has erected two Personal Parishes. The Personal Parish of Mary Immaculate in Oberarth is being erected for the faithful of the original cantons [NLM: i.e. Uri, Schwyz, Obwalden and Nidwalden], the Personal Parish of St. Maximilian Kolbe in Thalwil for the faithful of the canton Zurich.
Membership of a Personal Parish does not primarily depend on the place of residence, as with a normal parish, but on belonging to a group which is characterised by particularities of rite, language, or nationality. For instance, the Italian Mission in the cities of Zurich and Winterthur is likewise organised as a Personal Parish.
Pope Benedict XVI's motu proprio "Summorum Pontificum" of 7 July 2007 provides for the bishop erecting Personal Parishes for faithful attached to the Extraordinary Form of the Roman Rite. Such Personal Parishes have already been erected in various dioceses, e.g. in Rome, Blois, Straßburg, Quebec, Denver, Colorado Springs or Dallas.
