From the Latin littera pastoral, the original definition was an official letter addressed by a bishop to all members of the diocese. Pastoral letters may be issued in the Episcopal Church by the Presiding Bishop, the House of Bishops, or any diocesan bishop. The canons require that pastoral letters of the House of Bishops and diocesan bishops be read or otherwise distributed to the people. While the canons do not define a pastoral letter, one issued by a diocesan bishop is to address "points of Christian doctrine, worship, or manners."
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.