| MC | Master Clear | Computing, Assembly |
| CMR | Clear Master Relay | Computing, Hardware |
| 8Y6 | Leaders Clear Lake Airport, Clear Lake, Minnesota USA | Regional, Airport Codes |
| MPMB | Master of Project Management and Master of Business Administration | Academic & Science, Academic Degrees |
| MSci | Master in Science (Master of Natural Sciences at Cambridge) | Academic & Science, British Degree |
| MACM | Master-at-arms Master Chief Petty Officer | Governmental, Navy |
| PLMKWC | Please Let Me Know When Clear | Computing, Gaming |
| CE | Clear Everything | Miscellaneous, Unclassified |
| LMKWC | Let Me Know When (you are) Clear | Internet, Chat |
| 99704 | Clear, AK | Regional, ZIP Codes |
| CA | Clear All | Computing, Assembly |
| NC | Not Clear | Governmental, Transportation |
| LOGIC | Look Out Go If Clear | Miscellaneous, Unclassified |
| CB | Clear Bar | Miscellaneous, Unclassified |
| ACL | All Clear | Miscellaneous |
| CE | Clear | Computing, General |
| LMKWC | Let Me Know When you are Clear | Miscellaneous, Unclassified |
| DNC | Does Not Clear | Governmental, Military |
| SKC | SKy Clear | Academic & Science, Meteorology |
| CK | Clear Key | Computing, Cyber & Security |
| 24822 | Clear Fork, WV | Regional, ZIP Codes |
| CC | Clear Channel | Business, Companies & Firms |
| CTT | Clear To Transmit | Computing, Networking |
| 47426 | Clear Creek, IN | Regional, ZIP Codes |
| CBTK | Clear Between The Knots Mfg. Ltd. | Business, Companies & Firms |
| TGIC | The Ghost Is Clear | Miscellaneous, Funnies |
| CC | Clear Communication | Miscellaneous, Unclassified |
| C-C | Cast off and Clear | Governmental, Military |
| CTC | Clear To Close | Business, Mortgage |
| CSV | Clear SuperView | Miscellaneous, Photography & Imaging |
| CF | Clear Flash | Miscellaneous, Photography & Imaging |
| FIC | Front Is Clear | Governmental, Military |
| SC | Sector Clear | Computing, Gaming |
| BCOC | Be Clear on Cancer | Medical, Cancer |
| CCEE | Clear Clear Enter Enter | Computing, Software |
| 54005 | Clear Lake, WI | Regional, ZIP Codes |
| CTA | Clear to auscultation | Medical, Physiology |
| 50428 | Clear Lake, IA | Regional, ZIP Codes |
| CS | Clear Shadow | Miscellaneous, Clothes |
| ICC | Interstate Clear Cut | Miscellaneous, Unclassified |
| CWC | Clear Window Car | Miscellaneous, Unclassified |
| CC | Core Clear | Miscellaneous, Unclassified |
| 25044 | Clear Creek, WV | Regional, ZIP Codes |
| IBC | I Bank Clear | Business, Banking |
| PACL | Clear Mews,USA - AK | Regional, Airport Codes |
| CTB | Clear To Build | Miscellaneous, Construction |
| CQ | Clear Queue | Computing, Assembly |
| CG | Clear Graphics | Miscellaneous, Unclassified |
| CLS | Clear Last Screen | Computing, Assembly |
| CC | Carry Clear | Computing, Assembly |
| CSE | Clear Sky Elementary | Miscellaneous, Unclassified |
| CLS | CLear the Screen | Computing, DOS Commands |
| CD-N | Clear Day-Night | Governmental, Military |
| FCV | Foresight Clear | Business, London Stock Exchange |
| 21722 | Clear Spring, MD | Regional, ZIP Codes |
| LC | Loud and Clear | Governmental, Military |
| CAT | Clear-Air Turbulence | Governmental, Transportation |
| CE | Clear Entry | Miscellaneous, Unclassified |
| CLF | Clear Flags | Computing, Assembly |
| 36564 | Point Clear, AL | Regional, ZIP Codes |
