Catechism of the Catholic Church §1143 — excerpt
For the purpose of assisting the work of the common priesthood of the faithful, other particular ministries also exist, not consecrated by the sacrament of Holy Orders; their functions are determined by the bishops, in accord with liturgical traditions and pastoral needs.
This translation is under copyright, so only the cited words are quoted here. Follow the link for the full text. Translation: English translation of the Catechism of the Catholic Church, 2nd ed. (Libreria Editrice Vaticana), as posted at vatican.va.
Also cites: SC 29