  We explore the hypothesis that the Cabibbo angle is an expansion parameter
for lepton as well as quark mixing. Cabibbo effects are deviations from zero
mixing for the quarks but are deviations from unknown mixings for the leptons,
such that lepton mixing is veiled by a Cabibbo haze. We present a systematic
classification of parametrizations and catalog the leading order Cabibbo
effects. We find that the size of the CHOOZ angle is not always correlated with
the observability of CP violation. This phenomenological approach has practical
merit both as a method for organizing top-down flavor models and as a guideline
for planning future experiments.
