Conformant Texture Clamp?

My nVidia-based graphics card includes an option in Display Properties to “enable OpenGL conformant texture clamp behavior”.

Does anyone know what this means? Should I enable it for 3D games?

(If it matters, the video/graphics card is a Ti4200 128MB running on a P4 2.53GHz/533MHz fsb. 3D Mark2001 score is around 11,350).