Flex Circuit Drawing Details

Good afternoon all, I'm creating a relatively simple flex circuit board to be used instead of wiring loom which is something i've never done before. The application is for aviation for which i need good flammability performance such as V0 Rating. My question is is what notes do should i put on the drawings to get a flex. Normally i define something like IPC 4101/21 V0 Rated for a solid FR4 board. Is there a flex equivalent?