--- Types-Serialiser/Serialiser.pm	2013/10/28 15:28:44	1.4
+++ Types-Serialiser/Serialiser.pm	2013/10/28 21:52:22	1.5
@@ -186,6 +186,12 @@
 using the relevant form for perl objects. In CBOR for example, there is a
 registered tag number for encoded perl objects.
 
+The values that C<FREEZE> returns must be serialisable with the serialiser
+that calls it. Therefore, it is recommended to use simple types such as
+strings and numbers, and maybe array references and hashes (basically, the
+JSON data model). You can always use a more complex format for a specific
+serialiser by checking the second argument.
+
 =head2 DECODING
 
 When the decoder then encounters such an encoded perl object, it should