ios5 ARC what is the compiler flag to exclude a file from ARC?

I found the answer: to exclude the file from ARC, use the -fno-objc-arc flag in build phases>compile sources

the moral of this story is: once your project is in ARC and you have some files marked as no ARC, do not re-run the convert to ARC tool from Refactor>Convert to ARC. It will not restore your settings even if pre-check fails.

You can restore your settings for excluded files by removing references on them and then readd to project back