30 CFR § 7.409
Approval marking.
Approved electric cables, signaling cables, and splices shall be legibly and
permanently marked with the MSHA-assigned approval marking. For
electric cables and signaling cables, the marking shall appear at intervals
not exceeding 3 feet and shall include the MSHA-assigned approval number in
addition to the number and size (gauge) of conductors and cable type. For
cables containing electric conductors, the marking shall also include the
voltage rating. For splices, the marking shall be placed on the jacket so
that it will appear at least once on the assembled splice.
[57 FR 61222, Dec. 23, 1992]