§  9.15   Applicability.

   The rules in this subpart F apply to:

   (a) A person engaged in the business of manufacturing, importing,
   selling, or leasing multi-line telephone systems;

   (b) A person engaged in the business of installing, managing, or
   operating multi-line telephone systems;

   (c) Any multi-line telephone system that is manufactured, imported,
   offered for first sale or lease, first sold or leased, or installed
   after February 16, 2020.