Written note (4)
I believe the answer is:
memo
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">written note</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for memo that I've seen before include "- Currie, Br. politician" , "diplomatic communication?" , "Short note or message" , "A little something to be remembered" , "Reminder (abbr)" .)