Added 2 notes about the complexities of testing SyntaxErrors.
diff --git a/Doc/lib/libdoctest.tex b/Doc/lib/libdoctest.tex
index 2635486..92aa039 100644
--- a/Doc/lib/libdoctest.tex
+++ b/Doc/lib/libdoctest.tex
@@ -495,6 +495,37 @@
\item When the \constant{IGNORE_EXCEPTION_DETAIL} doctest option is
is specified, everything following the leftmost colon is ignored.
+\item The interactive shell omits the traceback header line for some
+ \exception{SyntaxError}s. But doctest uses the traceback header
+ line to distinguish exceptions from non-exceptions. So in the rare
+ case where you need to test a \exception{SyntaxError} that omits the
+ traceback header, you will need to manually add the traceback header
+ line to your test example.
+
+\item For some \exception{SyntaxError}s, Python displays the character
+ position of the syntax error, using a \code{\^} marker:
+
+\begin{verbatim}
+>>> 1 1
+ File "<stdin>", line 1
+ 1 1
+ ^
+SyntaxError: invalid syntax
+\end{verbatim}
+
+ Since the lines showing the position of the error come before the
+ exception type and detail, they are not checked by doctest. For
+ example, the following test would pass, even though it puts the
+ \code{\^} marker in the wrong location:
+
+\begin{verbatim}
+>>> 1 1
+ File "<stdin>", line 1
+ 1 1
+ ^
+SyntaxError: invalid syntax
+\end{verbatim}
+
\end{itemize}
\versionchanged[The ability to handle a multi-line exception detail,