A structured cap with a woven fabric crown and a fitted or adjustable closure typically falls under heading 6505 if the crown fabric is knitted, or under 6506 if it is woven. The key is the fabric construction of the crown panel. Visors and brims are considered part of the hat and do not change the heading, but their material may affect the subheading.

Heading 6507 covers components sold separately: hat linings, sweatbands, hat frames (the internal wire or buckram structure), outer covers, and chin straps. Finished hats — even unlined ones — classify under 6501 through 6506 based on their construction method and material. A sweatband sold as a standalone article goes in 6507; the same sweatband incorporated into a finished hat is part of the hat's classification.