The reason that so many people call it shaolin DO is because when grandmaster Sin The' came to the US he brought the teachings and TRADITIONS of his teacher, Ie Chang Ming, with him. Ie Chang Ming taught shaolin kung fu in indonesia where chinese martial arts were illegal. In order to continue teaching he adopted the japanese uniform, belt ranking system, and added DO to the end. This was the chinese art could still be practiced and anyone looking wouldnt catch on. Sin The', out of respect for his teacher, merely carried on this tradition within his school.