For a while now, a German Canonical Commentary on Summorum Pontificum by the German latinist and canon lawyer Fr. Gero P. Weishaupt has been available online. This commentary has now been published as a book, and the preface to this book was written by H.E. Archbishop Raimond L. Burke, Prefect of the Apostolic Signatura. The full text of the preface is available at the German website Summorum Pontificum. Here is an NLM translation of a passage of the preface which doubtlessly will raise great interest:In the second chapter of his commentary, Weishaupt answers a number of practical issues that arise regarding the implementation of Summorum Pontificum and result from recent changes to the discipline of the celebration of the sacraments, such as e.g. those regarding female altar servers or lay people who perform the ministry of lectors or extraordinary ministers of Holy Communion. To answer these questions , the commentary correctly applies two general canonical principles.The first principle requires that liturgical norms, which were in force in 1962, are to be diligently observed for the celebration of the Extraordinary Form of the Roman Rite, for these norms protect the integrity of the Roman rite as contained in the Missal of Blessed John XXIII. The second principle states that the subsequent liturgical discipline is only to be introduced in the Extraordinary Form, if this discipline affects a right of the faithful, which follows directly from the sacrament of baptism and serves the eternal salvation of their souls.The application of these two principles to the cases mentioned leads to the conclusion that neither the service at the altar by persons of the female sex nor the exercise of the lay ministries of lector or extraordinary minister of Holy Communion belong to the basic rights of the baptized. Therefore, these recent developments, out of respect for the integrity of the liturgical discipline as contained in the Missale Romanum of 1962, are not to be introduced into the Extraordinary Form of the Roman rite. The commentary presents here in an impressive manner that the mutual enrichment of both forms of the Roman rite is only possible if discipline peculiar to each of the two forms is accordingly carefully observed.