Minor issue (3)
(Other definitions for nit that I've seen before include "Louse; fool" , "Idiot, ass" , "Egg; fool" , "Young louse" , "Parasite's egg made of tin" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">minor issue?</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 age limit that I've seen before include "terminus a quo, say" , "Bar to those too old or too young" , "Regulation based on year of birth that sets down when one can no longer do something" , "I am legit (anag)" , "Maturity restriction" .)