%%
%% The LaTeX Companion, 3ed
%%
%% Example 6-2-18 on page I-446 in "Defining new column specifiers".
%%
%% Copyright (C) 2022 Frank Mittelbach
%%
%% It may be distributed and/or modified under the conditions
%% of the LaTeX Project Public License, either version 1.3c
%% of this license or (at your option) any later version.
%%
%% See https://www.latex-project.org/lppl.txt for details.
%%

\documentclass{tlc3exa}
\pagestyle{empty}
\setcounter{page}{6}
\setlength\textwidth{135.0pt}
%StartShownPreambleCommands
\usepackage{array}  \newcolumntype{Z}{clr}
%StopShownPreambleCommands

\begin{document}
\begin{tabular}{Z} one&two&three\\1&2&3 \end{tabular}
\end{document}