Hillary Clinton’s State Department staffers actually typed “C” in the body of emails — short for “confidential” — in an effort to alert the reader that it was classified information.

That’s the stunning admission FBI Director James Comey made during a House hearing today.

Congresswoman Martha McSally was discussing with Comey markings on classified documents, whether in the header or footer, or within the text.

“There were three emails,” Comey said, “that bore portion markings on a paragraph — not header markings or footer markings — for ‘C’ to indicate ‘confidential.’

“That was put on well down a chain, deeper, at a much lower level in the State Department. And, as I sit here I don’t know, I think we had concluded somebody had typed a talking for the secretary way down the chain and marked that portion with a ‘C.’

“So it wasn’t an uplift or a transfer, as you said, (but) a typing in the first instance and then putting a portion marking on it,” Comey said.

“But just to be clear it was the portion that was marked, not the document.”

McSally responded, “But still, on the unclassified system, they’re allowed to be transmitting confidential information?”

“No,” Comey answered, “because confidential information is classified — top secret, secret, confidential,” he said, referring to the classification rankings.

“So they had to have actually typed ‘confidential’ on an email chain, or they used transferable media,” McSally said.

“We have no indication of transferable media,” Comey responded, “What we think happened is somebody typed a talking point on an unclassed system, and then, for reasons that don’t make any sense to you and to me, marked it with a ‘C’ to indicate that portion was marked classified at the confidential level.

McSally seemed floored by his acknowledgment and said the revelation should be investigated.

“If you’re actually typing classified information and markings on an unclassified email, that’s a security violation and those people should be held accountable, as well,” McSally said.

Comey didn’t respond.