  In 1985, Hussein and McVoy [Nuc. Phys. A445 (1985) 124] elucidated a formula
for the evaluation of the nonelastic breakup ("stripping") contribution in
inclusive breakup reactions. The formula, based on the spectator core model,
acquires a particularly simple and appealing form in the eikonal limit, to the
extent that it has become the standard procedure to analyze single-nucleon
knockout reactions at intermediate energies. In this contribution, a critical
assessment of this formula is presented and its connection with other,
noneikonal expressions discussed. Some calculations comparing the different
formulae are also presented for the one-nucleon removal of $^{14}$O+$^{9}$Be
reaction at several incident energies.
