Volume II/29 "Molecular Constants Mostly from Microwave, Molecular Beam, and Sub-Doppler Laser Spectroscopy" is planned to appear as a series A, B, C and D1, D2, D3 for the diamagnetic, and E for the paramagnetic linear and polyatomic species, respectively. Like in the preseding volumes II/24 and II/19, which have appeared in the years around 1999 and 1992, respectively, the diamagnetic substances are arranged in the manner suggested by Hill ("Hill's...