Source: Dragon #346
You can weaken an opponent's spell resistance by warping his truename.
Prerequisite: Truespeak 12 ranks, any recitation feat, ability to speak utterances, must know your own personal truename.
Benefit: You lower a creature's spell resistance by s for 3 rounds by succeeding at a Truespeak check to say its personal Truename. The Truespeak DC to use this denouncement is 10 higher than normal.
This feat does not grant you knowledge of a creature's spell resistance. The reduction caused by this feat does not stack with itself, but you can use it multiple times on the same target to extend the duration of the reduction.