Distinctive mark (9)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">distinctive mark</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 signature that I've seen before include "time indicated by this?" , "ending to letter?" , "proof of identity" , "Identifying piece of writing, tune etc" , "Personal mark" .)
(Other definitions for stamp that I've seen before include "Cut out with a die" , "Mark of approval" , "Imprint, brand" , "squash?" , "Kind" .)