The Acceptable Identification of Goods and Services Manual is maintained by the United States Patent and Trademark Office and outlines the goods and services recognized by that office with respects to trademark registrations, where in order for an applicant to receive a trademark registration they must describe the goods/services and identify the classes the goods/service fall into.
The Acceptable Identification of Goods and Services Manual is a directory maintained by the United States Patent and Trademark Office outlining the different categories of goods and services recognized by that office with respect to trademark registrations, and setting forth the forty-two international classes into which those goods and services are divided. In order for an applicant to receive a trademark registration, that applicant must describe the goods and/or services to which the mark applies, and must identify the classes into which those goods and/or services fall. 
