5.12.4 ‘@|’: Literal vertical bar, or optional line break

In the TeX (documentation) part of a section, ‘@|’ inserts a vertical bar. Here’s a LaTeX example:

\begin{verbatim}
  The constructions @|x@| and |x| are very different.
\end{verbatim}

You might wish to try this out to see what FWEAVE produces.

In a code part, ‘@|’ inserts an optional line break in an expression.