The final August 1999 guidance explained how broadcast advertisements could satisfy the adequate-provision requirement. It is guidance, not a statute or regulation.
This guidance is intended to assist sponsors who are interested in advertising their prescription human and animal drugs, including biological products for humans, directly to consumers through broadcast media, such as television, radio, or telephone communications systems.
PDF p. 3; guidance introduction
The final August 1999 guidance explained how broadcast advertisements could satisfy the adequate-provision requirement. It is guidance, not a statute or regulation. The page was updated in 2002, but the guidance itself is dated August 1999.