For DAO96, What is the difference between Raw Sub-channels and R-W Sub-channels


I want to check when we do DAO-96 recording, what is the difference between raw-subchannel and R-W Sub-channels ?

If I want to do gapless raw recording, which one I should choose ? I found most test drives can support the raw-subchannel mode very well but cannot support R-W Sub-channels very well. I do not know why.