CTIA, representing The Wireless Assn., has petitioned the U.S. Supreme Court to block Berkeley’s cellphone “right to know” ordinance.

CTIA, whose slogan is “Everything Wireless,” argues that the ordinance forces cellphone retailers to deliver a misleading and controversial message to customers.

Berkeley says the message is “literally true” and that it has a legitimate interest in protecting the health of its residents.

The law was adopted in May 2015 and has been in effect since March, 2016. Berkeley has been waging a battle with CTIA for more than six years. The law requires cellphone retailers to provide consumers with the following notification:

“To assure safety, the Federal Government requires that cellphones meet radiofrequency (RF) exposure guidelines. If you carry or use your phone in a pants or shirt pocket or tucked into a bra when the phone is on and connected to a wireless network, you may exceed the federal guidelines for exposure to RF radiation. Refer to the instructions in your phone or user manual for information about how to use your phone safely.”

An appeals court ruled that government may compel commercial speech, absent any alleged false or deceptive communication, as long as the mandated message is “reasonably related to” any “more than trivial” governmental interest and is “literally true.”

The city prevailed in the federal district court and in the Ninth Circuit Court of Appeals. In October of last year, the appeal courts denied the CTIA’s request for a hearing before the full court.