Type of code (5)
I believe the answer is:
morse
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">type of code</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 morse that I've seen before include "Oxford detective" , "Endeavour" , "& 24 Across Encrypted language" , "Radio code inventor" , "10 [SLEUTH]" .)