Carmen Notes are secret notes that Carmen Sandiego writes for her crooks. These notes tell the crooks where to hide until Carmen returns to pick them up. The thieves always tear up the notes into shards to prevent ACME agents from tracking them.
In the game Where in Time is Carmen Sandiego? the player has to collect the note shards to find the hiding spot of each time thief. Since the notes are always in riddles, it's essential to use the Chronopedia to deduce the meaning of each riddle.