Mine

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    \begin{longtable}[H]{|p{1.5cm}|p{5.5cm}|p{5.0cm}|}
    \hline
    & Demand
    & Comment
    \tabularnewline\hline
    \endfirsthead
    \hline
    & Demand
    & Comment
    \tabularnewline\hline
    \endhead
    \endfoot
    \endlastfoot

}{
    \caption{Security requirements specification}
    \label{tbl:sec_req}
    \end{longtable}
}

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