Style of arrangement (6)
I believe the answer is:
format
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">style of arrangement</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for format that I've seen before include "Way of presentation" , "Secure firmly in position" , "Prepare (a disk) for data" , "The shape and size, of a book say" , "Style or arrangement of a TV programme" .)