Not for publication (3,3,6)
I believe the answer is:
off the record
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">not for publication</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 off the record that I've seen before include "Not to be made public" , "not to be broadcast" , "in a minute? No" , "In confidence" , "Taken from a disc" .)