(CNN) Donald Trump criticized Hillary Clinton on Sunday for not knowing what the "(C)" label meant when it was used on her State Department emails. But the Republican presidential nominee apparently doesn't know what it means either. "Lyin' Hillary Clinton told the FBI that she did not know the 'C' marking on documents stood for classified. How can this be happening?" Trump wrote on Twitter. John Noonan, a national security adviser to Jeb Bush and Mitt Romney, observed that Trump had incorrectly ascribed "classified" to the "C" markings -- they actually denote a lower security status, "confidential." Noonan wrote, "(C) stands for CONFIDENTIAL. Confidential, Secret, Top Secret are levels of classification. DoD Directive 5200.01."Donald Trump attacked Hillary Clinton after the FBI released notes from its interview with herTrump also hit Clinton over tightening polls, and highlighted revelations from the FBI's report on its investigation
The FBI had released a report Friday that detailed its investigation of _'s email use at the State Department along with notes from the bureau's interview with Clinton. For its part, the Clinton campaign said it was "pleased" by the release of the _ report on Friday. CNN reached out to the _ campaign for additional comment on the tweets, but did not immediately receive a response.