spelling - Lite instead of Light

I commonly see lite version, lite cream, etc. When is it acceptable to replace light with lite?

Is Lite already accepted as correct English or is it just an informal/incorrect spelling? Are there any differences in meaning between the two, or is one just a more informal variant of the other?

Answer

Oxford English Dictionary has an entry for it:

lite, adj.2 and n.6

Comm. Designating a manufactured product that is lighter (in weight, calorie content, etc.) than the ordinary variety, esp. (with capital initial) low-calorie beer. Freq. used postpositively.

1962 L. S. Sasieni Princ. & Pract. Optical Dispensing i. 17 On light-weight spectacles a small joint known as the ‘Lite-Elete’ is sometimes used.

But beyond that definition it wouldn't be interchangeable with light.

For example, the lite streamed in through the window, would be incorrect usage.