Reduction in Force Process for Excepted Employees

I am a title 50 USC 403, block 25 of SF-50 permanent employee and I can't find anywhere what our process would be if we had a RIF. Everything I find is for the competitive service. I'm 100% disabled vet with almost18yrs of Fed service plus 9yrs active duty (trying to buy that back now). Veterans status is not displayed on SF-50, and was told by HR our agency would not follow Title 5 RIF procedures as we have our own independent/exclusive separation authorities. Can someone point me in the right direction?