C65
C65 stands for:
- Commodore 65 , successor to the Commodore 64 that was never ready for series production
- Malignant neoplasm of the renal pelvis, classification according to ICD-10, see kidney cancer # classification
- Caldwell 65 , a galaxy from the Caldwell catalog
C6 / 5 stands for:
- C6 / 5 envelope size