An REO is not "milk's favorite cookie."

But Housing and Urban Development Secretary Ben Carson thought the foreclosure-related real estate acronym, which means "real estate owned," was the cream-filled chocolate cookie when grilled by Rep. Katie Porter, D-Calif., on Tuesday during a House Financial Services Committee hearing.

REO is property that's been turned over to a lender — whether that's the bank or a government agency — after a foreclosure process is complete.

Porter wanted to know about the high rate of foreclosures on homes insured by the Federal Housing Authority (FHA), which Carson's agency oversees.

“Do you know what an REO is?” Porter asked.

“Oreo?” a perplexed Carson answered.

“REO,” Porter repeated. “No, not an Oreo. An R-E-O.”

“Real estate?” Carson, a retired neurosurgeon, guessed. Then Porter to asked him what the “O” meant.

“The organization,” he replied.

Porter, who previously worked as a mortgage-settlement official in California, then explained the term to him.

“That’s what happens when a property goes to foreclosure,” she said. “We call it an REO. And FHA loans have much higher REOs — that means they go to foreclosure rather than loss-mitigation or to non-foreclosure alternatives such as short sales — than comparable loans at the GSEs (government-sponsored enterprises).”

Porter then needled Carson in a tweet after the hearing.

I asked @SecretaryCarson about REOs - a basic term related to foreclosure - at a hearing today. He thought I was referring to a chocolate sandwich cookie. No, really. pic.twitter.com/cYekJAkRag — Rep. Katie Porter (@RepKatiePorter) May 21, 2019

"I asked @SecretaryCarson about REOs — a basic term related to foreclosure — at a hearing today. He thought I was referring to a chocolate sandwich cookie. No, really," she wrote.

Carson took the flub in jest and tweeted a picture of a pack of Oreos and a note to send to Porter.

OH, REO! Thanks, @RepKatiePorter. Enjoying a few post-hearing snacks. Sending some your way! pic.twitter.com/q4MMTBWVUI — Ben Carson (@SecretaryCarson) May 21, 2019

"OH, REO! Thanks, @RepKatiePorter. Enjoying a few post-hearing snacks. Sending some your way!" he tweeted.

The official Oreo Twitter account jokingly responded to the moment with its own acronym for REO, which drew swift blowback from other users who called it insensitive.

𝗥𝗘𝗢 stands for "𝗥eally 𝗘xcellent 𝗢REO (cookie)." Everyone knows that. — OREO Cookie (@Oreo) May 21, 2019

Carson also had a moment of confusion during the hearing when Rep. Joyce Beatty, D-Ohio, asked him if he was familiar with OMWI, the Office of Minority and Women Inclusion.

Carson asked, "With who?"

"OMWI," Beatty repeated.

"Amway?" Carson asked.

However, Rep. Lee Zeldin, R-N.Y., later interjected at the hearing and noted that OMWI is not part of HUD — it's part of the Treasury Department.

“I just want to point out the reason why you wouldn’t recognize the term OMWI in HUD is that HUD doesn’t have OMWI," Zeldin said to Carson.