  We present a covariant decomposition of Einstein's Field Equations which is
particularly suitable for perturbations of spherically symmetric -- and general
locally rotationally symmetric -- spacetimes. Based upon the utility of the 1+3
covariant approach to perturbation theory in cosmology, the semi-tetrad, 1+1+2
approach presented here should be useful for analysing perturbations of a
variety of systems in a covariant and gauge-invariant manner. Such applications
range from stellar objects to cosmological models such as the spherically
symmetric Lemaitre-Tolman-Bondi solutions or the class of locally rotationally
symmetric Bianchi models.
