Variations on a theme: The ansatz of Stech for the quark mass matrices

I analyze the Ansatz of Stech for the quark mass matrices, showing that it is equivalent to a system of three linear equations among the squared moduli of the Cabibbo-Kobayashi-Maskawa matrix elements. I show that in the Ansatz of Stech the roles of ${\mathit{M}}_{\mathit{U}}$ and ${\mathit{M}}_{\mathit{D}}$ may be exchanged, and suggest a generalization of the Ansatz of Stech in which the top-quark mass may be higher than 100 GeV.