diff --git a/SWIG/Doc/engineering.html b/SWIG/Doc/engineering.html
index 6bdaadb38..996a41077 100644
--- a/SWIG/Doc/engineering.html
+++ b/SWIG/Doc/engineering.html
@@ -540,6 +540,30 @@ the type table and accessing the list of compatible types. If the
Scheme object passed was not a SWIG smob representing a compatible
pointer, a wrong-type-arg exception is raised.
+
+SWIG code calls scm_error on exception, using the following
+mapping:
+
+
+ MAP(SWIG_MemoryError, "swig-memory-error"); + MAP(SWIG_IOError, "swig-io-error"); + MAP(SWIG_RuntimeError, "swig-runtime-error"); + MAP(SWIG_IndexError, "swig-index-error"); + MAP(SWIG_TypeError, "swig-type-error"); + MAP(SWIG_DivisionByZero, "swig-division-by-zero"); + MAP(SWIG_OverflowError, "swig-overflow-error"); + MAP(SWIG_SyntaxError, "swig-syntax-error"); + MAP(SWIG_ValueError, "swig-value-error"); + MAP(SWIG_SystemError, "swig-system-error"); ++ +
+The default when not specified here is to use "swig-error". +See Lib/exception.i for details. + +