Naval flag (6)
I believe the answer is:
ensign
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">naval flag</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for ensign that I've seen before include "Badge, flag" , "Soldier; standard" , "Flag - junior American naval officer" , "US naval rank" , "Ship's flag and junior officer" .)