Hello,

I'm not sure about it, because it's against convention of using
``...'' in source file, but it's for '@section', so it's kind of
special case, which means it may be acceptable.

Attached picture shows before/after.

--- old/killing.texi    2020-05-03 01:31:57.259190700 +0200
+++ new/killing.texi    2020-05-06 23:39:16.942404300 +0200
@@ -452,7 +452,7 @@
  append to the text that @kbd{M-w} copied into the kill ring.

  @node Cut and Paste
-@section ``Cut and Paste'' Operations on Graphical Displays
+@section “Cut and Paste” Operations on Graphical Displays
  @cindex cut
  @cindex copy
  @cindex paste


S. U.