documentclass{article}
begin{document}
section{BLA}label{bla}
section{BOO}label{boo}
In Section~ref{bla} we do something.
end{document}

documentclass{article}

usepackage{refcheck}

begin{document}

begin{equation}label{eq:1}% Labelled and referred to
1+1=2
end{equation}

ref{eq:1}

begin{equation}label{eq:2}% Labelled but not referred to
1-1=0
end{equation}

begin{equation}% Not labelled nor referred to
1+1=0
end{equation}

begin{table}[h]
center
begin{tabular}{cc}
1 & 2 \
3 & 4 \
end{tabular}
caption{Numbers}label{tab:1}% Labelled but not referred to
end{table}

begin{figure}[h]label{fig:1}% Labelled but not referred to
caption{Foo}
end{figure}

end{document}