+The Texinfo settings @code{txicodequoteundirected} and
+@code{txicodequotebacktick} are both set in the manuals, so
+backticks (@code{`}) and apostrophes (@code{'}) placed within
+blocks of @code{@@code}, @code{@@example}, or @code{@@verbatim}
+are not converted to left- and right-angled quotes
+(@code{@quoteleft{} @quoteright{}}) as they normally are within
+the text, so the apostrophes in
+@q{@w{@code{@@w@{@@code@{@bs{}relative c''@}@}}}} will display
+correctly. However, these settings do not affect the PDF output
+for anything within a @code{@@samp} block (even if it includes a
+nested @code{@@code} block), so entering
+@q{@code{@@w@{@@samp@{@bs{}relative c''@}@}}} wrongly produces
+@q{@w{@code{@bs{}relative c@quoteright{}@quoteright{}}}} in PDF.
+Consequently, if you want to use a @code{@@samp@{@dots{}@}} block
+which contains backticks or apostrophes, you should instead use
+@q{@code{@@q@{@@code@{@dots{}@}@}}} (or
+@q{@code{@@q@{@@w@{@@code@{@dots{}@}@}@}}} if the block also
+contains spaces). Note that backslashes within
+@code{@@q@{@dots{}@}} blocks must be entered as @samp{@@bs@{@}},
+so the example above would be coded as
+@q{@code{@@q@{@@w@{@@code@{@@bs@{@}relative c''@}@}@}}}.
+