Originally, it was the 9-digit Standard Book Numbering (SBN) code and still was used in 1974; it was adopted as the international standard ISO 2108 in 1970. A similar, numeric identification, the International Standard Serial Number (ISSN), identifies periodical publications such as magazines. Since January 1, 2007, ISBNs are of 13 digits, like in Bookland EAN-13. The TC 46/SC 9 is responsible for the standard.