  Every simplest potential conservation law of any (1+1)-dimensional linear
evolution equation of even order proves induced by a local conservation law of
the same equation. This claim is true also for linear simplest potential
conservation laws of (1+1)-dimensional linear evolution equations of odd order,
which are related to linear potential systems. We also derive an effective
criterion for checking whether a quadratic conservation law of a simplest
linear potential system is a purely potential conservation law of a
(1+1)-dimensional linear evolution equation of odd order.
