デューイ十進分類法
Dewey himself held copyright in editions 1 to 6 (1876–1919). Copyright in editions 7–10 was held by the publisher, The Library Bureau. On the death of May Seymour, Dewey conveyed the "copyrights and control of all editions" to the Lake Placid Club Educational Foundation, a non-profit chartered in 1922. The Online Computer Library Center (OCLC) of Dublin, Ohio, US, acquired the trademark and copyrights associated with the Dewey Decimal Classification system when it bought Forest Press in 1988. In 2003 the Dewey Decimal Classification came to the attention of the U.S. press when OCLC sued the Library Hotel for trademark infringement for using the classification system as the hotel theme. The case was settled shortly thereafter.