\hd{Inline verbatim}
+\inlineverbon
Lo and behold: |a quick brown fox| {\showspacestrue |jumps over the lazy dog|} |!@#$%^&*()\_|
+\inlineverboff
+When turned off, vertical lines work as usually: $|a-b| \ge 0$.
+
\hd{Block verbatim}
\noindent Pre-verbatim