Texas Utilities Code - UTIL § 55.102. Applicability

(1) an identification service that is used in a limited system, including a central office based PBX-type system;

(2) information that is used on a public agency's emergency telephone line or on a line that receives the primary emergency telephone number (911);

(3) information exchanged between telecommunications utilities, enhanced service providers, or other entities that is necessary for the setting up, processing, transmission, or billing of telecommunications or related services;

(4) information provided in compliance with applicable law or legal process;  or

(5) an identification service provided in connection with a 700, 800, or 900 access code telecommunications service.