org-babel-tangle-comment-format-beg

org-babel-tangle-comment-format-beg is a variable defined in `ob-tangle.el'.
Its value is

"[[%link][%source-name]]"

Documentation:
Format of inserted comments in tangled code files.
The following format strings can be used to insert special
information into the output using `org-fill-template'.
%start-line --- the line number at the start of the code block
%file --------- the file from which the code block was tangled
%link --------- Org-mode style link to the code block
%source-name -- name of the code block

Whether or not comments are inserted during tangling is
controlled by the :comments header argument.

You can customize this variable.

This variable was introduced, or its default value was changed, in version 24.1 of Emacs.