Possible Clues:

• Untidy writing produced by son on edge
• Unreadable stuff from singular creep
• Lousy handwriting
• Lecture notes, usually
• Scribble primarily, freestyle?
• Small, gets to go on all fours and scribble
• Rough writer's output
• Illegible writing, first sign of sunstroke
• Scribble 'Half of screws to be removed by metal instrument'
• Doctor's penmanship, stereotypically