These rules govern how the system's components line up — sewer slope, tank & D-box levelness, lateral spacing and length, pressure distribution, fittings. The engine reads them when it lays out and checks a design. Edit them to match your practice. Rules tagged code are NYSDOH 75-A floors — you can only make them more conservative; an attempt to relax one snaps back to the code value. Rules tagged pref are your shop standards, freely editable.