Most if not all classified documents are classified paragraph by paragraph with the document itself marked at the highest level text or illustration within the document.
U would be UNCLASSIFIED
C would be the standard marking for CONFIDENTIAL.
S would be SECRET
TS would TOP SECRET
Higher level classifications would include TS/SCI and as an example and assuming there is a Stopwatch program: TS/STOPWATCH.
Putin, toasting with chill vodka comes to mind.