Figure sourcing in examples is now restricted to mu/econ.

example/mu/example.dtx

@@ -570,7 +570,9 @@ proofs.
     %% at 4 × 4 cm should be 1000 × 1000 px large or larger.
     \includegraphics[width=4cm]{fithesis/logo/mu/fithesis-base.pdf}
   \end{center}
+%<*econ>
   \emph{Source: <<Image Source>>}
+%</econ>
   \caption{The logo of the Masaryk University at 40\,mm}
   \label{fig:mulogo1}
 \end{figure}
@@ -585,7 +587,9 @@ proofs.
       \includegraphics[width=\textwidth]{fithesis/logo/mu/fithesis-base.pdf}
     \end{minipage}
   \end{center}
+%<*econ>
   \emph{Source: <<Image Source>>}
+%</econ>
   \caption{The logo of the Masaryk University at $\frac23$ and
     $\frac13$ of text width}
   \label{fig:mulogo2}
@@ -605,7 +609,9 @@ proofs.
     morning. \\
     \bottomrule
   \end{tabularx}
+%<*econ>
   \vskip\abovecaptionskip\emph{Source: <<Table Source>>}
+%</econ>
   \caption{A weather forecast}
   \label{tab:weather}
 \end{table}