Latex sty
newenvironment
Required parameter.
\newenvironment{declaration}[1]{everythingbefore}{-everythingafter}
Optional parameter, only need to provide default value.
\newenvironment{declaration}[1][default]{everythingbefore}{-everythingafter}
In latex.sty
\newenvironment{declaration}[1]{\begin{alwayssingle} \pagestyle{empty}
\begin{center}
\vspace*{1.5cm}
{\Large \bfseries #1}
\end{center}
\vspace{0.5cm}
\begin{quote}}
{\end{quote}\end{alwayssingle}}
Usage:
\begin{declaration}{title}
Content \end{declaration}