Code 02-Surface shop, yard, etc., at an underground mine;
Code 30-Mill operation, preparation plant, or breaker, including associated shops and yards;
Code 03-Surface strip or open pit mine, including shop and yard;
Code 04-Surface auger coal operation on a coal mine, including shop and yard;
Code 05-Surface culm bank or refuse pile at a coal mine, including shop and yard;
Code 06-Dredge mining, including shop and yard;
Code 12-Other surface mining;
Code 17-Independent shops;
Code 99-Office facilities.
Code 01-Vertical shaft;
Code 02-Slope/Inclined shaft;
Code 03-Face;
Code 04-Intersection;
Code 05-Underground Shop/Office;
Code 06-Other.
Code 01-Longwall;
Code 02-Shortwall;
Code 03-Conventional/stoping;
Code 05-Continuous Miners;
Code 06-Hand Loading;
Code 07-Caving;
Code 08-Other.
30 C.F.R. §50.20-6
Secs. 103 (a) and (h), and 508, Pub. L. 91-173 , as amended by Pub. L. 95-164 , 91 Stat. 1297, 1299, 83 Stat. 803 (30 U. S. C. 801 , 813 , 957 )