D.C. Code § 32-216: Street-trades badges — Required.

No minor under 16 years of age shall work at any time, or be employed or permitted or suffered to work at any time, in any of the trades or occupations mentioned in § 32-215, unless such minor shall have procured and shall wear in plain sight while so working a badge as hereinafter provided, issued by the Board of Education, and unless the minor complies with all the legal requirements concerning school attendance.