30 C.F.R. § 75.1202-1 Temporary notations, revisions, and supplements.
Title 30 - Mineral Resources
(a) Mine maps shall be revised and supplemented at intervals of not more than 6 months. (b) Temporary notations shall include: (1) The location of each working face of each working place; (2) Pillars mined or other such second mining; (3) Permanent ventilation controls constructed or removed, such as seals, overcasts, undercasts, regulators, and permanent stoppings, and the direction of air currents indicated; (4) Escapeways designated by means of symbols.
Title 30: Mineral Resources
PART 75—MANDATORY SAFETY STANDARDS—UNDERGROUND COAL MINES
Subpart M—Maps
§ 75.1202-1 Temporary notations, revisions, and supplements.
