16 CFR § 300.6 - Labels to be avoided.

Stamps, tags, labels, or other marks of identification, which are insecurely attached, or which in the course of offering the product for sale, selling, reselling, transporting, marketing, or handling incident thereto are likely to become detached, indistinct, obliterated, illegible, mutilated, inaccessible, or inconspicuous, shall not be used.