diff --git a/docs/InternalsManual.html b/docs/InternalsManual.html
index 9e8a21e..5d32d8d 100644
--- a/docs/InternalsManual.html
+++ b/docs/InternalsManual.html
@@ -1152,7 +1152,10 @@
     any evaluatable subexpression to be accepted as an integer constant
     expression.</li>
 <li><b><tt>__builtin_constant_p</tt></b>: This returns true (as a integer
-    constant expression) if the operand is any evaluatable constant.</li>
+    constant expression) if the operand is any evaluatable constant.  As a
+    special case, if <tt>__builtin_constant_p</tt> is the (potentially
+    parenthesized) condition of a conditional operator expression ("?:"), only
+    the true side of the conditional operator is considered.</li>
 <li><b><tt>__builtin_choose_expr</tt></b>: The condition is required to be an
     integer constant expression, but we accept any constant as an "extension of
     an extension".  This only evaluates one operand depending on which way the