The groff manual indexes "\|" which is output in the LaTeX output as
\index[es]{\textbackslash{}"|@\texttt{\textbackslash{}"|}}%
However this leads to an error:
! Extra }, or forgotten \endgroup.
<recently read> }
l.72 \item \texttt{\textbackslash{}|}}
, 186
?
es.idx has a line
\indexentry{\textbackslash{}"|hyperindexformat{\@\texttt{\textbackslash{}"|}}}{1
which becomes in es.ind
\item \texttt{\textbackslash{}|}}, 186
" is supposed to escape the first | but this doesn't work properly.
The only thing I could find is this page from 2014:
https://tex.stackexchange.com/questions/176931/how-to-escape-character-in-index
but this only treats | in the math context. A commenter there says it
"confuses hyperref".
The "hyperindexformat" texts appears to be something added by hyperref.
Does anybody know (or know where we could ask) how to escape a | character
in an index entry correctly?
