Saint abbreviation

Just for fun:

\documentclass{article}
\usepackage{xparse}
\usepackage{fontspec}

\setmainfont{Libre Bodoni}

\NewDocumentCommand{\frabbr}{sm}{%
  \IfBooleanTF{#1}{\dofrabbr{}{#2}}{\dofrabbr{\hfil}{#2}}%
}

\newcommand{\dofrabbr}[2]{%
  \vbox to\fontcharht\font`T {%
    \ialign{%
      #1##\hfil\cr
      \relscriptsize#2\cr
      \noalign{\nointerlineskip\vfill}
      .\cr
    }%
  }%
}

\makeatletter
\newcommand{\relscriptsize}{%
  \check@mathfonts\fontsize\ssf@size\z@\selectfont
}
\makeatother

\begin{document}

\bfseries
\begin{tabular}{@{}c@{}}
6\frabbr*{me} Arr\frabbr{T} \\
BOULEVARD \\
S\frabbr{T} GERMAIN
\end{tabular}

\end{document}

The following should produce what you want. You can use an optional argument to specify another letter than T (e.g. t):

\documentclass[]{article}

\newsavebox\myboxA
\newsavebox\myboxB
\newcommand\saint[1][T]
  {%
    \begingroup
    \sbox\myboxA{S}%
    \usebox\myboxA
    \sbox\myboxB{\tiny#1}%
    \rlap{\raisebox{\dimexpr\ht\myboxA-\ht\myboxB}{\usebox\myboxB}}%
    \makebox[\wd\myboxB]{.}%
    \endgroup
  }

\begin{document}
\saint\ Germain
\saint[t] Germain
\end{document}