diff --git a/common-trace-format-specification.md b/common-trace-format-specification.md
index fd49e59..b2ea3fb 100644
--- a/common-trace-format-specification.md
+++ b/common-trace-format-specification.md
@@ -1,4 +1,4 @@
-# Common Trace Format (CTF) Specification (v1.8.2)
+# Common Trace Format (CTF) Specification (v1.8.3)
 
 **Author**: Mathieu Desnoyers, [EfficiOS Inc.](http://www.efficios.com/)
 
@@ -464,6 +464,9 @@ enum {
 }
 ~~~
 
+The mappings in the enumeration type do not have to be exhaustive. Unlisted
+values are implementation defined.
+
 ### 4.2 Compound types
 
 Compound are aggregation of type declarations. Compound types include