This addendum provides changes to TSB-31-C@ Telecommunications ?C Telephone Terminal Equipment ?C Rationale and Measurement Guidelines for U.S. Network Protection. Clause 2 contains an addition to the Suggested Equipment List in subclause 5.5 of TSB-31-C. Clause 3 provides text and figures for completely replacing those found in Clause 15 of TSB-31-C. The other clauses in TSB-31-C are not affected. Words that appear in Underlined Italics in this addendum are intended as instructions to the reader.