  Symmetry properties of conservation laws of partial differential equations
are developed by using the general method of conservation law multipliers. As
main results, simple conditions are given for characterizing when a
conservation law and its associated conserved quantity are invariant (and, more
generally, homogeneous) under the action of a symmetry. These results are used
to show that a recent conservation law formula (due to Ibragimov) is equivalent
to a standard formula for the action of an infinitesimal symmetry on a
conservation law multiplier.
