Warning sign (3,4)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">warning sign</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for red flag that I've seen before include "The ... ..., anthem of the British Labour Party" , "Emblem of socialist revolution or danger" , "A number of revolutionaries" , "Warning signal" , "Emblem of socialism" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">warning sign</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 omen that I've seen before include "Gloomy sign" , "Portent, prophetic indicator" , "Forewarning, harbinger" , "Portent of things to come" , "Straw in the wind" .)