I've been requiring a possitive connection between footings and stem walls which usually isn't an issue with contractors that provide vertical reinforcement. However, in my area vertical reinforcement is not required for the standard 2' tall stem wall per Table R404.1.2(2). I have a contractor that is challenging my plan review red line requiring doweling or a keyway between the stem wall and footing. At this point I can only offer it up as a "suggestion" due to the lack of a code reference. Any suggestions/comments?