\documentclass[basic, infoblock, lang=english]{onlinebrief24}

\setreturnaddress{Jane Smith, 12 Oak Street, Bristol BS1 4DJ}

\setrecipient{
  Example Services Ltd \\
  Mr. John Smith \\
  24 Market Road \\
  London SW1A 1AA
}

\setsubject{Question about your maintenance contract}
\setplace{Bristol}
\setdate{2026-03-27}
\setyourref{RM-7741}
\setyourmessage{2026-03-18}
\setourref{OB24-2026-0322}
\setourmessage{2026-03-20}
\setcontactname{Jane Smith}
\setcontactphone{0123 / 456 789}
\setcontactfax{0123 / 456 780}
\setcontactemail{service@example.com}

\begin{document}

\begin{letter}{}

\opening{Dear Mr. Smith,}

Thank you for your message. This example shows the new
\texttt{infoblock} in the upper-right header area as a classic
information block with fixed DIN-style fields.

Fields that are not set are hidden automatically, so the block stays compact
even when only a few entries are used.

\closing{Kind regards}

\end{letter}

\end{document}