An antenna modeling tool labels a transmission line with only Z0 and length. A user passed z0, length, vf, k1 and k2 positionally, so they landed in the wrong fields, "VF 0.27, a crossed line, almost no loss. The Schematic still read '50 Ω, 10 m', so nothing on screen showed the slip." The proposal is to print VF, matched loss and the transposed flag on every line.