I'm pretty sure "D/P" stands for "Disabled/Pregnant". I live in Shanghai, so I can tell you that special lines like that actually mean diddly squat. The combination of nouveau mega-rich with crazy entitlement issues + ignoramuses who don't use their brains ensures that this is the case (Don't believe me? Check out the boarding area for UA857 (SFO-PVG) for a small preview!!). Superbly annoying to anyone who actually believes in waiting your turn