The Diocese of Gaylord decribes the Permanent Diaconate this way...
A deacon is an ordained minister of the Catholic Church. By his ordination, the deacon is called publicly and committed to service in the name of Jesus Christ in the Church and in the world. The docment Permanent Deacons in the U.S.: Guidelines on Their Formation and Ministry lists the guidelines of the National Conference of Catholic Bishops. It clearly states that "deacons are ordained by the local bishop for the service of the diocesan church...a deacon is to be committed to a broad range of the diocese's needs and concerns" (#30-32).
Three general areas of dioconal ministry are distinguished: The Ministry of Love and Justice; the Ministry of the World of God; and the Ministry of the Liturgy.
You can read more about the Diocese of Gaylord Permanent Diaconate Program at http://dioceseofgaylord.org/inside/the-permanent-diaconate--189/.