CARB: California Air Resources Board
stovee - I looked at your profile.
My header has the CARB # welded on a primary, most that are CARB legal do. My intake came with a sticker. A cat back exhaust doesn't need any documentation. If your equipment is legal it should have come with the documentation. Call the company and ask if it's legal and if they will send you the documentation. The number is what is needed; that is what identifies the part. I live in CA, and they are strict here. Definitely need the documentation to get it smogged which is needed to register. Haven't been pulled over and hassled, although I believe it does happen here. I'm don't how it works in other states. I do know emission laws are getting strict everywhere.