Purpose and Scope This document specifies guidelines for the assignment of line numbers within the 800-855-XXXX resource@ hereafter called 800-855 numbers@ which will only be used for the purpose of accessing public services on the Public Switched Telephone Network (PSTN) intended for the deaf@ hard of hearing or speech impaired. For the purposes of these guidelines services for the deaf@ hard of hearing or speech impaired will be defined as those which are used generally to benefit this particular user community@ e.g.@ services used by deaf@ hard of hearing or speech impaired persons to access a Telecommunications Relay Service (TRS)@ Message Relay Service (MRS) or any other entity via text telephone service (TTY). These guidelines were developed by industry consensus process under the auspices of the Industry Numbering Committee (INC). These guidelines are expected to apply throughout the NANP Area unless the affected administrations direct otherwise. These guidelines do not supersede controlling appropriate NANP Area governmental or regulatory principles@ procedures and requirements.