That “S” in IRS must stand for “silent.”

You’d think so, anyway, by the way these people handle questions from congressmen.

Faced with questions over procurement contracts worth up to a half-billion dollars, an IRS official invoked the Fifth Amendment on Wednesday, halting questions about whether he had helped a friend land those deals.

According to a Politico report, Gregory Roseman, a former deputy of acquisitions for the scandal-wracked agency, wouldn’t even identify his boss during an appearance before the House Oversight and Government Reform Committee.

Roseman’s invocation of his right against self-incrimination made him the second high-ranking IRS official in a month to adopt such protections. Lois Lerner, the IRS director of tax-exempt groups for the agency, took the Fifth on May 22 during questioning by the same committee.

But before she did so, Lerner made a statement declaring, “I did nothing wrong.” That led Committee Chairman Darrell Issa, R-Calif., and some other members to question whether, having once made a statement, Lerner could invoke the constitutional protection after all.

The committee is scheduled to vote on Friday on whether to call Lerner back for more questioning. The incident has already led Rep. Mo Brooks, R-Ala., to introduce a bill, quickly dubbed “the Lerner Rule,” which would allow federal employees who refuse to answer questions or who lie to congressional committees to be fired without a civil service hearing.

In Wednesday’s incident, the panel was trying to question Roseman about whether his allegedly “cozy relationship” with Strong Castle Inc. and its president, Braulio Castillo, helped that company land contracts worth a potential $500 million.

According to Politico, Issa asked Roseman who he reports to at the IRS, but Roseman clammed up.

“On the advice of the counsel, I respectfully decline to answer any questions and invoke my Fifth Amendment privilege to remain silent,” Roseman said.

When Issa tried to question him further, about when he first heard of Strong Castle, Roseman repeated his statement.

Roseman was then allowed to leave the hearing.

Yep. The “S” is for silent.