Using XeLatex and Polyglossia package with Greek as default Language I need to replace in lists the 6th item from Stigma to SigmaTau (στ). How Can I?

Question

I need the number of the sixth list element to be (στ)

Answer 1

You first want to remove the ʹ at the end of numbers, then to patch the relevant macros that produces the stigma to do “sigma tau”.

\documentclass[a4paper]{article}
\usepackage{polyglossia}
\usepackage{enumitem}
\setmainlanguage{greek}
\setmainfont{Libertinus Serif}
\makeatletter
\patchcmd{\anw@true}{ʹ}{}{}{}
\patchcmd{\gr@num@i}{Ϛ}{στ}{}{}
\patchcmd{\gr@Num@i}{\MakeUppercase{Ϛ}}{ΣΤ}{}{}
\makeatother
\begin{document}
\begin{enumerate}
\item A
  \begin{enumerate}
  \item B
  \item C
  \item D
  \item E
  \item F
  \item G
  \item H
  \end{enumerate}
\item B
  \begin{enumerate}[label=(\Alph*)]
  \item B
  \item C
  \item D
  \item E
  \item F
  \item G
  \item H
  \end{enumerate}
\end{enumerate}
\end{document}