Nikon T* 600/800

[Songyun]

I recently bought the Nikon T* 600/800 lens set. When I receive the lens, I see that the front barrel has engraved Nikon 600mm and 800mm, but without 1200mm. I googled a few photos, and found some of the Nikon T* 600 lens has engraved 1200mm on the front barrel. Does this make a difference? If I get an 1200mm rear element later, Can I use it with the front element with only 600/800 engraved?

[Huub]

I am in the same situation with the 360-500-720 set: only markings for the 360 - 500 combination. But i fugured that adding the 720 rear element would be no problem, as it would just add another stop. So the f16 marking for the 500mm should be read as f22 for the 720mm. For your set it would be more or less the samen.