| macaroni | machine shop | machine tool accessories |
| magazine distributors | magnesium foundries | magnetic recording media |
| mail-order houses | maker industrial | malt beverages |
| management consulting services | manifold business forms | man made |
| manufacturers agents | manufacturers representatives | manufacturing industries |
| marble | marble products manufacturers | marble products natural |
| marina | marine cargo handling | marine contractors |
| marine insurance | marking devices | martial arts schools |
| masonry contractors | massage school | mattress manufacturers |
| meat market | meat packing plants | meat products |
| meats | meat wholesale | medical clinic |
| medical dental assistant technician schools | medical doctors | medical instruments |
| medical laboratories | medical school | medical service plans |
| membership organizations | membership sports | men's clothing retail |
| men's trousers | men's work clothing | men clothing |
| men coats | mens clothing stores | men slacks |
| men suits | mental health clinics | merchandising machine operators |
| metal-household furniture | metal cans | metal coating |
| metal finishing | metal forming type | metal polishing |
| metal service centers | metals service offices | metal stamping |
| metal stamping manufacturers | metal working machinery | mexican restaurant |
| middle school | millwork | millwork contractors |
| millwork manufacturers | mineral conservation | mineral wool |
| mini bike dealers | mini bikes | mining machinery |
| miscellaneous accessory stores | miscellaneous apparel stores | miscellaneous business credit institutions |
| miscellaneous commercial sectors | miscellaneous fabricated wire products | miscellaneous food stores |
| miscellaneous general merchandise stores | miscellaneous homefurnishings | miscellaneous nonmetallic minerals |
| miscellaneous personal service | miscellaneous publishing | miscellaneous retail stores |
| misses' dresses | misses' outerwear | misses' suits |
| mobile home community | mobile home dealers | mobile home manufacturers |
| mobile home parks | mobile homes | molder |
| monetary policy | montessori school | mortgage banker |
| mossaic work | motel | motion picture equipment |
| motion picture film distributions | motion picture film exchanges | motion pictures |
| motion picture supplies | motion picture theaters | motorcycle |
| motorcycle bicycle | motorcycle bicycle manufacturers | motorcycle dealers |
| motorcycle parts manufacturers | motor home | motor scooter dealers |
| motor scooters | motor vehicle | motor vehicle accessories |
| motor vehicle new parts | motor vehicle parts | motor vehicle supplies |
| movie theaters | moving supplies | moving supplies renting |
| muffins | mufflers engine | museum |
| musical instruments | musical instrument stores | music school |
