Example LaTeX listings with mixed alphanumeric keywords

keywords.tex

\documentclass[12pt]{article}

\usepackage{xcolor}
\usepackage{listings}

\renewcommand{\ttdefault}{pcr}

\definecolor{Black}{gray}{0.0}
\definecolor{Blue}{rgb}{0.12,0.29,0.53}

\lstset{
  basicstyle=\color{Black}\ttfamily, %
  keywordstyle=[1]\color{Blue}\ttfamily\bfseries, %
}

\lstdefinelanguage{mylang}{ %
%  keywords={FOO,BAR,BAZ,ARG}, %
%  otherkeywords={1234,XYZ1234,XYZ1234HelloWorld}, %
  alsoletter=0123456789,
  keywords={FOO,BAR,BAZ,ARG,1234,XYZ1234,XYZ1234HelloWorld}, %
}

\begin{document}
\begin{lstlisting}[numbers=none,breaklines=true,caption={},language=mylang]
FOO
BAR
BAZ
ARG
1234
XYZ1234
XYZ1234HelloWorld
\end{lstlisting}
\end{document}