General Order 95
Section VII
Detailed Construction Requirements for Trolley and Electric Railway
Contact and Feeder Conductors and Their Supporting Messengers,
Span Wires, Etc. (Class T Circuits)
72.4 Marking
The provisions of Rule 52.4
apply to crossarms supporting Class T conductors except that any crossarm
(either of wood or metal) or any appliance used in lieu thereof attached to
poles or structures which support only Class T conductors of more than 750
volts, or such conductors and private communication conductors of the same
ownership, need not be marked as supporting high voltage conductors.