TDD - Telecommunication Device for the Deaf - device which allows conversation to take place over the telephone by sending typed messages through phone lines to the TDD screen.
Title VI - Title VI of the Civil Rights Act of 1964 - Prohibits discrimination on the basis of race, color, or national origin by recipients of Federal financial assistance.
TTY - Teletypewriter - a precursor to the TDD.
Undue Hardship - Significant difficulty or expense - Undue hardship is determined on a case by case basis considering such factors as the overall size and financial resources of the employer, the type of the employer's operation, and the nature and cost of the accommodation needed. (See page 22680, section 84.12(b) and page 22688 of the Section 504 regulation, subpart B, item 16 for more information.)