Trump's lawyers said classified Mar-a-Lago documents could be privileged because they contain his handwritten notes.
Trump is backing up an order preventing DOJ from reviewing classified records seized from his home.
A "special master" appointed to review those records held an initial hearing Tuesday.
The Justice Department has not minced words in its appeal for access to classified materials seized from former President Donald Trump's Mar-a-Lago home. Without the ability to review those records, it argued, the "government and the public would suffer irreparable harm."
But on Tuesday, Trump's lawyers suggested that those concerns - and clear classification markings - may not be enough to overcome the power of the former president's pen, or Sharpie.
"The fact the documents contain classification markings does not necessarily negate privilege claims," Trump's lawyers said in a new filing with the US Court of Appeals for the 11th Circuit. They went on to note that according to court documents, some of the classified records seized from Mar-a-Lago "allegedly contain what appear to be President Trump's handwritten notes."
"Those notes could certainly contain privileged information; further supporting the need for an independent, third-party review of these documents," they added.
Tuesday's filing came in response to the Justice Department's appeal of a court order temporarily halting its review of about 11,000 documents seized from Mar-a-Lago, including more than 100 that were marked classified.
Judge Aileen Cannon refused last week to stay her ruling and appointed Raymond Dearie, a former chief judge of the federal court in Brooklyn, to serve as special master - an outside arbiter who reviews materials and sifts out any that could be covered under attorney-client or executive privilege.
The Justice Department, in appealing Cannon's order, said it "impedes the government's efforts to protect the nation's security." But lawyers for the former president said handwritten notes trumped the urgency of that concern.
Trump has also frequently claimed without evidence that he had a "standing order" to declassify all the records that were moved to Mar-a-Lago. But more than a dozen of his former aides told CNN they had no knowledge of such an order, and Trump's legal team has not made the claim in any of its filings.
In court filings, Trump's lawyers have not echoed his declassification claims, but they have asserted that a current president has absolute authority to declassify information. On Monday, they said the government "has not proven" the records with classified markings were still classified, adding that "this issue is to be determined later."
Dearie, the newly appointed special master, held an initial hearing Tuesday to address how his review process will unfold over the next two months. Ahead of that hearing, Trump's lawyers opposed Dearie's request for more information about the classification status of the seized documents.
The response was notable because Trump's lawyers acknowledged the possibility of an indictment on charges related to the removal of records from the White House.
Handing over information about records' classification status would force Trump to "fully and specifically disclose a defense" that he might use in the event of a "subsequent indictment," his lawyers argued.
The FBI searched Mar-a-Lago on August 8 as part of an inquiry into possible violations of the Espionage Act and other laws, according to a search warrant that was unsealed with redactions. In court filings, the Justice Department has noted that the Espionage Act makes it a crime to retain government records pertaining to the national defense regardless of classification status.
The Justice Department's inquiry is also examining possible violations of laws that criminalize the concealment, removal, and destruction of government records - also regardless of classification level.