Both Sacramentary and Missal have long histories of use as titles of liturgical books in Catholic liturgical history. However, in this case the simple answer is that the official ICEL translators of the second edition of the Missale Romanum translated the title as “Sacramentary,” this translation was approved by the Vatican, the ICEL translators of the third edition, that is due to be published in the coming months, translated the same title as “Roman Missal”, this new translation of the title was also approved by the Vatican. From a point of view of the function of the book, an argument could really be made that Sacramentary is a better description. However if you are looking at a true translation of the Latin title then Roman Missal is better. In addition, outside of the US, most other English speaking countries used the same ICEL translation of the second edition, but the book was titled “Roman Missal.” Another factor is that the current Roman Missal is published as a collection of a few books, the Lectionary for Mass (in its various volumes) and the Book of Gospels are also technically part of the Roman Missal (whereas the Scripture readings were contained in the same book as the Mass prayers in pre-conciliar editions of the Missal). In this case it might be better to give the book the title “The Roman Missal: The Sacramentary.” But as this is not the title of the Latin editio typica, that is being translated, and given the fact that it took many years to translate the volume that will appear before Advent, it is very unlikely to change title. In any event, it is much more important to receive the new volume of the Roman Missal and to use it well to enhance our liturgical celebrations than to worry about the aptness of the actual title.