Colorful cover sheets are used for classified information. According to documents unearthed by the Federation of American Scientists, that is the case.

FBI agents seized 11 sets of documents from Donald Trump's home office in Florida.

Only those with government-issued security clearances were allowed to read the documents. Experts say there is no proof that Trump followed procedure to declassify the documents.

The levels of classified documents are classified according to their importance to national security.

The Confidential cover sheet has three colors: blue, Secret and Top Secret. The green cover sheet is used for unclassified information.

There are older versions of these cover sheets.

Man putting secret documents in bag
A red Secret Cover sheet
US Department of Defense

According to the National Archives Code of Federal Regulations, the cover sheets are supposed to protect classified information.

The sheets should be attached to the document until it is classified or destroyed.

The top half of the document's cover warns that those who handle the information are required to protect it from unauthorized disclosure.

The US General Services Administration has a list of cover forms. The forms were last updated in August of 1985.

The cover sheets can be ordered through the US GSA.

According to the National Archives, the US GSA gives labels for US property that have classified government information on them.