Abbreviation: VC = "Vibration Compensation" (Tamron)

The abbreviation VC means "Vibration Compensation" and is seen on Tamron products.

Explanation from Tamron

amron’s Unique State-of-the-Art In-Lens Image Stabilization System
Handheld camera shake is the leading cause of blurry and unsharp pictures. Several leading companies now make lenses with built-in optical image-stabilization systems that sense the amplitude and direction of the shake and compensate by moving optical groups within the lens. Tamron’s exclusive new Vibration Compensation (VC) system that’s built into the Tamron AF28-300mm F/3.5-6.3 XR Di VC LD Aspherical (IF) Macro and the Tamron AF18-270mm F/3.5-6.3 Di-II VC LD Aspherical (IF) Macro lenses performs a similar function, but it executes it much more effectively due to its innovative breakthrough design.

While other image-stabilization systems can only correct the effects of camera shake in horizontal or vertical planes, Tamron’s VC system uses a tri-axial configuration that employs three pairs of driving coils and low-function ball bearings placed around the shake-compensating optical group to produce, in effec

See examples of effected products

Tamron 28-300mm F3.5-6.3 XR Di VC

See links

tamron-usa.com