1) Concerning the Episcopal Church. Used in this sense, the adjective "Episcopal" is always capitalized. For example, "The Episcopal liturgy will be used at the wedding." Similarly, "The Episcopal priest attended the ecumenical gathering." 2) Concerning a bishop or bishops. Used in this sense, the adjective "episcopal" is not always capitalized. For example, an episcopal ring is a ring worn by a bishop as a sign of the bishop's office. See Episcopalian.
Glossary definitions provided courtesy of Church Publishing Incorporated, New York, NY,(All Rights reserved) from "An Episcopal Dictionary of the Church, A User Friendly Reference for Episcopalians," Don S. Armentrout and Robert Boak Slocum, editors.