PalaInstantCast is a small addon that helps Retribution Paladins with a buff called 'Art of War'. If that buff is active 'Exorcism' and 'Flash of Light' can be casted instant. In that case PalaInstantCast displays a letter (e.g. 'I') on your 'Exorcism' and 'Flash of Light' button so that you directly know that they are instant.