ABA Accessibility Standard for GSA Facilities Pocket Guide
708.4 Residential Dwelling Unit Communication Systems.
Communications systems between a residential dwelling unit and a site, building, or floor entrance shall comply with 708.4.
The common use or public use system interface shall include the capability of supporting voice and TTY communication with the residential dwelling unit interface.
The residential dwelling unit system interface shall include a telephone jack capable of supporting voice and TTY communication with the common use or public use system interface.