Conn. Agencies Regs. § 14-280-1
A portable sign permitted or required to be used when transporting children in a motor vehicle in accordance with subsection (a) of section 14-280 of the Connecticut General Statutes shall be constructed of a planar, non-frangible material which is sufficiently rigid that it will not bend, deform or incline when attached to a motor vehicle traveling at highway speeds, shall not have sharp edges, and shall be mounted to the motor vehicle in a manner capable of withstanding a wind of fifty (50) miles per hour without separating from the motor vehicle when the vehicle is traveling at highway speeds. Perforations may be made in a sign to reduce wind resistance if such perforations do not interfere with the visibility of the words on the sign.
Conn. Agencies Regs. § 14-280-1