Questions about whether Freddie Mac somehow violated its federal charter when it misclassified certain mortgage securities transactions have been raised on Capitol Hill. Rep. Richard Baker, R-LA, has sent a letter to the Office of Federal Housing Enterprise Oversight asking the agency to investigate whether Freddie had misclassified MBS pools and mismanaged “certain credit rate instruments” and “credit guarantees” in order to cover risks that its federal charter requires it to farm out to