org: comments

 
 14.8.2.9 ‘:comments’
 ....................
 
 By default code blocks are tangled to source-code files without any
 insertion of comments beyond those which may already exist in the body
 of the code block.  The ‘:comments’ header argument can be set as
 follows to control the insertion of extra comments into the tangled code
 file.
 
    • ‘no’ The default.  No extra comments are inserted during tangling.
    • ‘link’ The code block is wrapped in comments which contain pointers
      back to the original Org file from which the code was tangled.
    • ‘yes’ A synonym for “link” to maintain backwards compatibility.
    • ‘org’ Include text from the Org mode file as a comment.  The text
      is picked from the leading context of the tangled code and is
      limited by the nearest headline or source block as the case may be.
    • ‘both’ Turns on both the “link” and “org” comment options.
    • ‘noweb’ Turns on the “link” comment option, and additionally wraps
      expanded noweb references in the code block body in link comments.