The information on terms of carriage of mails is mails is found in?

The information on terms of carriage of mails is found in the post office guide. A post office guide is a publication that contains information on postal rates, regulations, and services provided by the postal system. It provides detailed information on the terms of carriage of mails, including delivery standards, postage rates, restrictions, and other relevant information related to mailing services. Therefore, if you need information on the terms of carriage of mails, you can consult the post office guide.