org-edit-src-region-extra

org-edit-src-region-extra is a variable defined in `org-src.el'.
Its value is

nil

Documentation:
Additional regexps to identify regions for editing with `org-edit-src-code'.
For examples see the function `org-edit-src-find-region-and-lang'.
The regular expression identifying the begin marker should end with a newline,
and the regexp marking the end line should start with a newline, to make sure
there are kept outside the narrowed region.

You can customize this variable.