  The Stein couplings of Chen and Roellin (2010) vastly expanded the range of
applications for which coupling constructions in Stein's method for normal
approximation could be applied, and subsumed both Stein's classical
exchangeable pair, as well as the size bias coupling. A further simple
generalization includes zero bias couplings, and also allows for situations
where the coupling is not exact. The zero bias versions result in bounds for
which often tedious computations of a variance of a conditional expectation is
not required. An example to the Lightbulb process shows that even though the
method may be simple to apply, it may yield improvements over previous results
that had achieved bounds with optimal rates and small, explicit constants.
