%%
%% The LaTeX Companion, 3ed
%%
%% Example 6-9-1 on page I-496 in "keyvaltable --- Separating table data and formatting".
%%
%% 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{165.0pt}

  \usepackage{keyvaltable}

\NewKeyValTable{cities}{ name: align=c, head=city;
  country: default = ??, format = \textbf;
  note:    align = X,    format = \raggedright, default = \ ---;
  visited: hidden }

%StartShownPreambleCommands
\usepackage{keyvaltable}
% \NewKeyValTable{cities}{...} as defined above
%StopShownPreambleCommands

\begin{document}
\begin{KeyValTable}[nobg]{cities}
  \Row{name=Mainz, note=Birthplace of Gutenberg}
  \Row[format=\color{blue}]
      {name=New York, country=USA, visited=yes}
\end{KeyValTable}
\end{document}
