| Abbreviation | Definition |
|---|---|
| CLSD | Certified Lodging Security Director |
| CLSS | Certificate in Life Span Studies |
| CLSS | Certification in Life Span Studies |
| CLSS | Certified Lean Six Sigma |
| CLSS | Certified Life Safety Specialist |
| CLSS | Certified Lodging Security Supervisor |
| CLSSGB | Certified Lean Six Sigma Green Belt |
| CLT | Certified Laboratory Technician |
| CLT | Certified LEAP Therapist |
| CLTC | Certificate for Long Term Care |
| CLTC | Certification for Long Term Care |
| CLTC | Certification in Long Term Care |
| CLTC | Certification of Long Term Care |
| CLTD | Certified in Logistics Transportation and Distribution |
| CLVT | Certified Low Vision Therapist |
| CLWM | Certified Landscape Water Manager |
| CLWS | Certified LAN and WAN Specialist |
| CLWT | Certified Lymphedema and Wound Therapist |
| CLYL | Certified Laughter Yoga Leader |
| CMAA | Certified Medical Administrative Assistant |