UNIMARC is the universal version of the MARC standard for bibliographic and similar information in machine-readable formats, which is maintained by the IFLA. The manual for authority control within the standard was published in 1991 and 2001, and is updated again here to reflect other recent publications. After introductory material and guidelines for using the manual, the formats are set out for the identification block and the coded information block in the directory, and for control subfields such as variant access point block, classification and entity history block, and national use block. Examples of the formats are provided. The manual is not indexed. Annotation ©2010 Book News, Inc., Portland, OR (booknews.com)