But since .AVI files are "containers" you are free to use any CODEC you wish in RAW or otherwise. If you claim this .AVI is created without CODECS you have truly discovered something new.

All AVI files I'd found contain the FOURCC code to identify how to decode what's inside the AVI.

HOWEVER one can create a MPEG file and rename it to .AVI and while it's not an AVI Windows players still figure it out.

Great question that rips open a big confusing area for most.
Bob