| Acronym | Meaning |
| CBJ | Covered Blow Job |
| CD9 | Code 9 (parents Are Around) |
| CF | Coffee Freak |
| CFV | Call For Vote |
| CHA | Click Here Asshole |
| CIAO | Goodbye (in Italian) |
| CICO | Coffee In, Coffee Out |
| CICYHW | Can I Copy Your Home Work? |
| CID | Consider It Done |
| CID | Crying In Disgrace |
| CLD9? | Cloud 9? (Stoned?) |
| CLM | Career Limiting Move |
| CM | Call Me |
| CMAP | Cover My Ass Partner |
| CMF | Count My Fingers |
| CMIW | Correct Me If I'm Wrong |
| CMU | Crack Me Up |
| CNP | Continued In Next Post (forums) |
| COB | Close Of Business |
| COD | Change Of Dressing |
| COF$ | Church Of Scientology |
| COS | Change Of Subject |
| CRAFT | Can't Remember A F*cking Thing |
| CRAP | Cheap Redundant Assorted Products |
| CRAT | Can't Remember A Thing |
| CRAWS | Can't Remember Anything Worth A Sh*t |
| CRB | Come Right Back |
| CRBT | Crying Real Big Tears |
| CRDTCHCK | Credit Check |
| CRS | Can't Remember Sh*t |
| CRTLA | Can't Remember The Three-Letter Acronym |
| CS | Career Suicide |
| CSA | Cool Sweet Awesome |
| CSL | Can't Stop Laughing |
| CSN | Chuckle, Snicker, Grin |
| CT | Can't Talk |
| CTA | Call To Action |
| CTC | Choking The Chicken |
| CTC | Care To Chat |
| CTO | Check This Out |
| CU | Cracking Up |
| CU | See You |
| CUATU | See You Around The Universe |
| CUIMD | See You In My Dreams |
| CUL | See You Later |
| CUL8R | See You Later |
| CULA | See You Later Alligator |
| CUNS | See You In School |
| CUOL | See You OnLine |
| CUWTA | Catch Up With The Acronyms |