Reef safe, with the exception of ornamental crustaceans (as mentioned). However, these fish require a lot of open sandy area, and usually do best in dedicated setups.
They tend to rub their rostrums against the tank walls, esp at first, so peeps who keep them use about 6" of dark paper around the lower portion of the tank.
They really aren't a "Oh, cool fish...I think I'll pop one into my reef" type of critter.