Among topics it addresses are inclusive language -- one of the most sharply contested issues in recent years in the English-speaking world -- and requirements for exact translation of Latin texts in other languages.
The 34-page instruction covers other areas ranging from detailed rules on how bishops' conferences develop translations, the Vatican's role in the process, and procedures for creating new liturgical texts not contained in the normative Latin ritual books.
The Vatican Congregation for Divine Worship and the Sacraments posted the instruction in English, French and Latin on the congregation's page of the Vatican Web site late May 7.
It describes the new rules as setting the stage "for a new era of liturgical renewal."
The document replaces the 1969 Vatican instruction titled "Comme le Prevoit" (French for "as foreseen"), which has guided translators of Latin liturgical texts around the world for more than 30 years.
Unlike the 1969 text, which gave translators latitude for relatively free translations in a number of areas, the new one says the normative Latin texts of the Roman Missal and other liturgical rites "must be translated integrally and in the most exact manner, without omissions or additions in terms of their content and without paraphrases or glosses."
The new instruction is titled "Liturgiam Authenticam" ("The Authentic Liturgy") and is subtitled in English, "On the Use of Vernacular Languages in the Publication of the Books of the Roman Liturgy."
"Liturgical texts should be considered as the voice of the church at prayer" and therefore "should be free of an overly servile adherence to prevailing modes of expression," it says.
On the issue of gender-related terms and inclusive language, the instruction warns that an insistence on changing traditional usage "is not necessarily to be regarded as the effect or the manifestation of an authentic development of the language as such."
It adds, "Even if it may be necessary by means of catechesis to ensure that such words continue to be understood in the 'inclusive' sense just described, it may not be possible to employ different words in the translations themselves without detriment to the precise intended meaning of the text, the correlation of its various words or expressions, or its aesthetic qualities."
The instruction says: "In particular: To be avoided is the systematic resort to imprudent solutions such as a mechanical substitution of words, the transition from the singular to the plural, the splitting of a unitary collective term into masculine and feminine parts, or the introduction of impersonal or abstract words, all of which may impede the communication of the true and integral sense of a word or an expression in the original text. Such measures introduce theological and anthropological problems into the translation."
In language about God and the persons of the Trinity, it says, "The truth of tradition as well as the established gender usage of each respective language are to be maintained."
It orders no tampering with the Christological term "Son of Man" and says that traditional usage of "fathers" is to be retained for the patriarchs and kings of the Old Testament or the Fathers of the Church.
More generally, it says that, "in translating biblical passages where seemingly inelegant words or expressions are used, a hasty tendency to sanitize this characteristic is ... to be avoided."
Where some texts may be difficult to understand or interpret correctly, it says, "It is the task of catechists or the homilist to transmit that right interpretation of the texts that excludes any prejudice or unjust discrimination on the basis of persons, gender, social condition, race or other criteria, which has no foundation at all in the texts of the sacred liturgy.
"Although considerations such as these may sometimes help one in choosing among various translations of a certain expression," it adds, "they are not to be considered reasons for altering either a biblical text or a liturgical text that has been duly promulgated."
The new instruction covers a wide range of other concerns.
It warns against using a translation of the Roman ritual texts as "an avenue for the creation of new varieties or families of rites."
It specifies that, for each language adopted for liturgical use in a country, "only one approved translation" of the Bible should be used for the liturgy in that country.
It says the "Nova Vulgata Editio" (the Latin New Vulgate Edition) of the Bible, promulgated by Pope John Paul II, is the authoritative text of reference for Bible passages with "varying manuscript traditions."