C.I. 29160; C.I. Direct Red 23 (VAN); C.I. Direct Red 23, disodium salt; C.I. Direct Red 23; C.I. Direct Red 23, disodium salt; Direct Red 23; Scarlet 4BS; disodium 4-oxo-3-(2-{4-[(2-oxoethyl)amino]phenyl}hydrazinylidene)-6-({[(6E)-5-oxo-6-(2-phenylhydrazinylidene)-7-sulfonato-5,6-dihydronaphthalen-2-yl]carbamoyl}amino)-3,4-dihydronaphthalene-2-sulfonate; (3E)-3-{2-[4-(acetylamino)phenyl]hydrazinylidene}-4-oxo-7-({[(6E)-5-oxo-6-(2-phenylhydrazinylidene)-7-sulfo-5,6-dihydronaphthalen-2-yl]carbamoyl}amino)-3,4-dihydronaphthalene-2-sulfonic acid; Direct Scarlet 4BS