Which section contains information on meal preparation for commercial first class mail?

The section that contains information on meal preparation for commercial first-class mail is the one focused on mail preparation. This section is critical as it outlines the specific guidelines and requirements for preparing mail for shipment. Proper meal preparation ensures that mailpieces are the correct size, weight, and format according to postal regulations. This is especially important for commercial first-class mail because adherence to set standards is necessary for timely and efficient delivery. The guidelines may cover various aspects, including packaging, labeling, and the use of necessary documentation, which are all crucial for effective mail handling and service delivery in the postal system.