  The calculation presented in "A neoclassical calculation of rotation profiles
and comparison with DIII-D measurements" by Stacey, Johnson, and Mandrekas,
[Physics of Plasmas, 13, (2006)], contains several errors, including the
neglect of the toroidal electric field, an unphysical expression for the
electrostatic potential, and an unevaluated relation among its parameters. An
alternative formulation is discussed.
