For copyfile(), be explicit that src and dst are file names; that was only
implied.
diff --git a/Doc/lib/libshutil.tex b/Doc/lib/libshutil.tex
index ad96bd3..8ff5367 100644
--- a/Doc/lib/libshutil.tex
+++ b/Doc/lib/libshutil.tex
@@ -19,8 +19,9 @@
 
 
 \begin{funcdesc}{copyfile}{src, dst}
-  Copy the contents of \var{src} to \var{dst}.  If \var{dst} exists,
-  it will be replaced, otherwise it will be created.
+  Copy the contents of the file named \var{src} to a file named
+  \var{dst}.  If \var{dst} exists, it will be replaced, otherwise it
+  will be created.
 \end{funcdesc}
 
 \begin{funcdesc}{copyfileobj}{fsrc, fdst\optional{, length}}