Source: Dragon #346
You can shield allies from your foe by warping his truename.
Prerequisite: Truespeak 12 ranks, any recitation feat, ability to speak utterances, must know your own personal truename.
Benefit: As an immediate action on a foe's turn, you can designate one of your allies as someone your foe cannot target with spells or spell-like abilities until the end of his turn. This only affects the foe's ability to target spells or spell-like abilities for the rest the round. This does not protect your ally from area effects. You can designate yourself as an ignored target. You must succeed on a Truespeak check to say your foe's personal truename. The Truespeak DC to use this denouncement is 10 higher than normal.
You can only choose a specific combination of attacker and protected target three times per encounter, but you may choose any particular attacker or protected target at will.