Note the exception raised when parameter to chr() is out of range.
diff --git a/Doc/lib/libfuncs.tex b/Doc/lib/libfuncs.tex
index 2fba45a..1aedf64 100644
--- a/Doc/lib/libfuncs.tex
+++ b/Doc/lib/libfuncs.tex
@@ -102,7 +102,8 @@
Return a string of one character whose \ASCII{} code is the integer
\var{i}, e.g., \code{chr(97)} returns the string \code{'a'}. This is the
inverse of \function{ord()}. The argument must be in the range [0..255],
- inclusive.
+ inclusive; \exception{ValueError} will be raised if \var{i} is
+ outside that range.
\end{funcdesc}
\begin{funcdesc}{cmp}{x, y}