Vice President Biden's F-bomb, dropped Tuesday during the signing of the health care reform bill, was Washington's version of a "wardrobe malfunction" -- but so far, the FCC doesn't appear to be investigating. 

A Federal Communications Commission official had "no knowledge" of any complaint being filed about Biden's now-famous comment when asked by on Thursday. 

And unless and until there's a complaint, there's no investigation. That's the way the FCC works. 

But that doesn't mean Biden's blurt couldn't get networks that aired it into trouble. 

The comment, for those who may have missed it, came as Biden was introducing President Obama before the bill signing. In a remark caught on the live mikes, he informed the president that enacting a sweeping health policy pursued in Washington for decades was a "big f---ing deal." 

It was loud enough to be heard, and soft enough to go unnoticed if you weren't looking for it. It lasted two seconds. Plenty of channels carried it, though it was bleeped for mass consumption on subsequent replays. 

But the FCC does have a policy banning "fleeting expletives" -- a ban that was upheld by the Supreme Court last year in a case dealing with F-bombs dropped by singer Cher and reality show diva Nicole Richie on live broadcasts. Broadcasters violating the ban can be fined.

That policy was put in place after U2's Bono said "f---ing brilliant" during the Golden Globes in 2003. 

There are exceptions to the rule. Cable channels pretty much have free reign. The networks have leeway to air profane material outside the window of 6 a.m. and 10 p.m.

But Tuesday's signing happened shortly before noon.

The FCC official offered no additional details about the commission's take on Biden. 

"We don't speculate," the official said.

Whether or not the comment ever leads to a complaint, it's been a huge hit -- on the Internet, in the media and even at the White House

Biden, talking to a fundraising crowd Wednesday, said Obama told him afterward at a presidential briefing: "You know what the best thing about yesterday was? Joe's comment." 

Obama told Biden he tried to have a T-shirt with his "BFD" comment on it, but couldn't have it ready in time.

ROW 2, SEAT 4: Biden's Bleeping Internet Sensation