2010 ADA Standards for Accessible Design Pocket Guide
217.5 Shelves for Portable TTYs.
Where a bank of telephones in the interior of a building consists of three or more public pay telephones, at least one public pay telephone at the bank shall be provided with a shelf and an electrical outlet in accordance with 704.5.
EXCEPTIONS: 1. Secured areas of detention and correctional facilities where shelves and outlets are prohibited for purposes of security or safety shall not be required to comply with 217.5.
2. The shelf and electrical outlet shall not be required at a bank of telephones with a TTY.