This is out of the 2000 Chicago code.
18-27-250.64. Grounding Electrode Conductor Installations.
Grounding electrode conductors shall be installed as specified in (a) through (e) of this section.
Raceways for grounding electrode conductors shall not contain other conductors. The outer finish of an insulated grounding
electrode conductor need not be identified except that it shall not be white or green. Flexible conduit and armored cable shall be
permitted to be used in existing buildings for grounding purposes only where this ground is concealed or a major portion of the ground is concealed. An approved nonferrous metal tag shall be attached to the ground clamp giving warning against its removal.
Russ
