\multicolumn{2}{c}{\textbf{Request}}\\
$1$ & SDS send code \verb#'s'#\\
$2-3$ & SDS length as a 16-bit integer\\
- $n$ & Value of the SDS identifier\\
+ $2-3$ & Value of the SDS identifier\\
\midrule
\multicolumn{2}{c}{\textbf{Response}}\\
$1$ & SDS numeric identification\\