Please refer to \index in \pagenote with splitindex option (for multiple index)
With the following MWE no epub could be made with tex4ebook.
\documentclass{report}
\usepackage{index}
\usepackage[texindy,splitindex]{imakeidx}
\usepackage[hyperindex,hidelinks]{hyperref}
\usepackage[page]{pagenote}
\input{pagenote-index-usageB.tex}% See code below
\makeindex[program=texindy,name=Names,title=Names]
\makeindex[program=texindy,name=Something,title=Something]
\makepagenote
\begin{document}
First index.\index[Something]{First index}
Sentence.\pagenote{First pagenote without index.}
\clearpage
Emph index.\index[Something]{Emph index@\emph{Emph index}}
pagenote and index.\pagenote{Second pagenote with index.\protect\is[Something]{Index inside second pagenote|seealso{Emph index}}}
\clearpage
Third pagenote.\pagenote{\emph{Emph index word}.\protect\is[Something]{Emph index@\emph{Emph index}}\protect\is[Something]{Emph index@\emph{Emph index}|see{Index inside second pagenote}}}
Namenindex\index[Names]{Namenindex}
\printnotes
\printindex[Something]
\printindex[Names]
\end{document}
with help of the file pagenote-index-usageB.tex
\newcommand\pn[2]{\hyperpage{#2}\hyperlink{pn:#1}{A#1}}
\makeatletter
\let\if@nopnote\iffalse % just for the example
\renewcommand{\notenuminnotes}[1]{%
\edef\tempnumber{#1}%
\edef\temppgnumber{\thepage}%
{\normalfont #1.} }
\ExplSyntaxOn
\NewDocumentCommand {\is} { om }{%
\if@nopnote
\IfValueTF { #1 } {
\index[#1]{#2}
}{
\index{#2}
}
\else
\hypertarget{pn:\tempnumber}{}%
\IfValueTF { #1 } {
\thomkrates_pagenoteindex:nene { #1 } { \tempnumber } { #2 } { \temppgnumber }
}{
\thomkrates_pagenoteindex:ene { \tempnumber } { #2 } { \temppgnumber }
}
\fi
}
\cs_new_protected:Nn \thomkrates_pagenoteindex:nnnn
{
\index [#1] { #3 | pn {#2}{#4} }
}
\cs_generate_variant:Nn \thomkrates_pagenoteindex:nnnn { nene }
\cs_new_protected:Nn \thomkrates_pagenoteindex:nnn
{
\index { #2 | pn {#1}{#3} }
}
\cs_generate_variant:Nn \thomkrates_pagenoteindex:nnn { ene }
\ExplSyntaxOff
\makeatother
pdflatex does a good job and the multiple index is working as intended with index entries pageAnotenum: xAn ... 324A84 for example.
But when producing an epub with tex4ebook the first \index{} gives an error..."extra }"
Is there a chance to get an epub with multiple index and pagenote-indexing?
Thank your for support.