Hint about [\] trick to avoid quad backslashes.
diff --git a/Doc/libregex.tex b/Doc/libregex.tex
index 9766c2c..d3f44ba 100644
--- a/Doc/libregex.tex
+++ b/Doc/libregex.tex
@@ -22,9 +22,10 @@
they are followed by an unrecognized escape character.
\emph{However}, if you want to include a literal \dfn{backslash} in a
regular expression represented as a string literal, you have to
-\emph{quadruple} it. E.g.\ to extract \LaTeX\ \samp{\e section\{{\rm
+\emph{quadruple} it or enclose it in a singleton character class.
+E.g.\ to extract \LaTeX\ \samp{\e section\{{\rm
\ldots}\}} headers from a document, you can use this pattern:
-\code{'\e \e \e \e section\{\e (.*\e )\}'}. \emph{Another exception:}
+\code{'[\e ] section\{\e (.*\e )\}'}. \emph{Another exception:}
the escape sequece \samp{\e b} is significant in string literals
(where it means the ASCII bell character) as well as in Emacs regular
expressions (where it stands for a word boundary), so in order to