  A stationary subset S of a regular uncountable cardinal kappa reflects fully
at regular cardinals if for every stationary set T subseteq kappa of higher
order consisting of regular cardinals there exists an alpha in T such that S
cap alpha is a stationary subset of alpha. We prove that the Axiom of Full
Reflection which states that every stationary set reflects fully at regular
cardinals, together with the existence of n-Mahlo cardinals is equiconsistent
with the existence of Pi^1_n-indescribable cardinals. We also state the
appropriate generalization for greatly Mahlo cardinals.
