When three or more telephones are provided in a bank, one shall be designed to accommodate a portable text telephone ( TTY) and shall be equipped with a shelf and an electrical outlet within or adjacent to the telephone enclosure. The telephone handset shall be capable of being placed flush on the surface of the shelf. The shelf shall be at least nine inches wide by 12 inches deep (9" x 12" = 229mm x 305mm) and shall have six inches (6" = 152mm) minimum vertical clearance.
521 CMR, § 37.9