Back in the days when the SWMM manual was written (and dinosaurs still roamed the earth), it was probably assumed that modelers knew Fortran. Alas, Fortran is now becoming the Latin of computer languages. A quick Google search for fortran format statements turned up numerous promising looking narratives, including this one: http://www.phy.nau.edu/~bowman/PHY52...17_format.html

Mitch Heineman
HeinemanM@CDM.COM