% !TeX program = xelatex
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\documentclass[12pt]{article}
\usepackage[margin=2cm]{geometry}

% Type=Any|Archaic|Classical
% LineWidth=Auto|<dimension> (e.g. 0.85\textwidth)
% ObscureLetters enables koppa/digamma (and transliteration KA/KO/W)
% resetDirection=Page|Paragraph (default Page)
% inLine=True renders only bracketed spans, e.g. normal [mirrored] text
\usepackage[Type=Classical,ObscureLetters=On]{boustrophedon}

\begin{document}

\section*{Boustrophedon template}

\boustrophedon{ΔΗΜΟΣ ΑΘΗΝΑΙΩΝ \\ ΤΙΜΩΝ ΑΝΔΡΑ ΑΓΑΘΟΝ \\ ΚΑΙ ΣΩΦΡΟΝΑ}

\bigskip

\startBoustrophedon[Type=Archaic]
ANDRA MOI ENNEPE MOUSA POLYTROPON OS MALA POLLA PLANGCHTHE
\stopBoustrophedon

\bigskip

Normal text with \boustrophedon[inLine=True]{only [THIS PART] mirrored} inline.

\end{document}