Rock Shox Reba Team 2006 100/115mm

Changing travel on Rock Shox Reba Team 2006 100/115mm to 85mm ?

Just installed my new fork - a Reba Team DualAir with PopLock remote on my hardtail.

I want to use it with 85 mm travel, but on the outer legs it says I can only choose between 100mm/115mm. Howcome? The Reba 2006 are only sold in 85mm/100mm configuration as far as I know.

Are the internals/externals in my Reba different than on the normal 85/100mm Rebas, or is it possible to rebuild it to 85mm?

Thanks for inputs!