Use the \note and \warning macros where appropriate.
diff --git a/Doc/mac/libctb.tex b/Doc/mac/libctb.tex
index 9950a41..337ca0f 100644
--- a/Doc/mac/libctb.tex
+++ b/Doc/mac/libctb.tex
@@ -65,9 +65,9 @@
asynchronously, with the callback routine being called upon
completion.
-\emph{Note:} for reasons beyond my understanding the callback routine
+\note{For reasons beyond my understanding, the callback routine
is currently never called. You are advised against using asynchronous
-calls for the time being.
+calls for the time being.}
\end{memberdesc}