the Paris Principles was to serve as a basis for international standardization in cataloging. Most of the cataloging codes that were developed worldwide since that time have followed the Paris Principles. Cataloging codes Cataloging codes prescribe which information about a bibliographic item is included in the entry and how this information is presented for the user; It may also aid to sort the entries in printing (parts of) the catalog. Currently, most cataloging codes are similar to, or even based on, the International Standard Bibliographic Description (ISBD), a set of rules produced by the International Federation of Library Associations and Institutions (IFLA) to describe a wide range of library materials. These rules organize the bibliographic description of an item in the following eight areas: title and statement of responsibility (author or editor), edition, material specific details (for example, the scale of a map), publication and distribution, physical description (for example, number of pages), series, notes, and standard number (ISBN). There is an initiative called the Bibliographic Framework (Bibframe) that is "an initiative to evolve bibliographic description standards to a linked data model, in order to make bibliographic information more useful both within and outside the library community." The most commonly used cataloging code in the English-speaking world was the Anglo-American Cataloguing Rules, 2nd edition (AACR2). AACR2 provides rules for descriptive cataloging only and does not touch upon subject cataloging. AACR2 has been translated into many languages, for use around the world. The German-speaking world uses the Regeln für die alphabetische Katalogisierung (RAK), also based on ISBD. The Library of Congress implemented the transition to RDA from AACR2 in March 2013. In subject databases such as Chemical Abstracts, MEDLINE and PsycINFO, the Common Communication Format (CCF) is meant to serve as a baseline standard. Different standards prevail in archives and museums, such as CIDOC-CRM. Resource Description and Access (RDA) is a recent attempt to make a standard that crosses the domains of cultural heritage institutions. Digital formats Most libraries currently use the MARC standards—first piloted from January 1966 to June 1968 —to encode and transport bibliographic data. These standards have seen critiques in recent years for being old, unique to the library community, and difficult to work with computationally. The Library of Congress developed BIBFRAME in 2011, an RDA schema for expressing bibliographic data. BIBFRAME was revised and piloted in 2017 by the Library of Congress, but still is not available