Guiding maxim (5)
I believe the answer is:
motto
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">guiding maxim</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 motto that I've seen before include "It may be proverbial" , "device" , "(Family) maxim" , "Repeated theme in music" , "Catchphrase" .)