Anglican eucharistic theology is diverse in practice, reflecting the comprehensiveness of Anglicanism. Its sources include prayer book rubrics, writings on sacramental theology by Anglican divines, and the regulations and orientations of ecclesiastical provinces. The principal source material is the Book of Common Prayer (abbr: BCP), specifically its eucharistic prayers and Article XXVIII of the Thirty-Nine Articles. Article XXVIII comprises the foundational Anglican doctrinal statement about the Eucharist, although its interpretation varies among churches of the Anglican Communion and in different traditions of churchmanship such as Anglo-Catholicism and Evangelical Anglicanism.