Recommended but not compulsory (8)
I believe the answer is:
advisory
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">recommended but not compulsory</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 advisory that I've seen before include "Recommended but not compulsory" , "helping" , "Making recommendations" , "Recommending" .)