\begin{psyntax}{Hint directives}{hintdirective}
\synt{hint\ directive}  
\begin{stack} \\
\lit*{Deprecated} 
  \begin{stack}
    \\ 
    \synt{string\ constant}
  \end{stack}
\\
\lit*{Experimental} \\
\lit*{Platform} \\
\lit*{Unimplemented}
\end{stack}
\end{psyntax}