diff --git a/jsonschema-core.xml b/jsonschema-core.xml
index bbdb3e46..7917f02b 100644
--- a/jsonschema-core.xml
+++ b/jsonschema-core.xml
@@ -200,6 +200,15 @@
A JSON document to which a schema is applied is known as an "instance".
+
+ JSON Schema is defined over "application/json" or compatible documents,
+ including media types with the "+json" structured syntax suffix.
+
+
+ Among these, this specification defines the "application/schema-instance+json"
+ media type which defines handling for fragments in the URI,
+ and the "schema" media type parameter.
+
-
-
- JSON Schema is designed to fully work with "application/json" documents,
- as well as media types using the "+json" structured syntax suffix.
-
-
- Some functionality that is useful for working with schemas is
- defined by each media type, namely media type parameters and
- URI fragment identifier syntax and semantics. These features are
- useful in content negotiation and in calculating URIs for specific
- locations within an instance, respectively.
-
-
- This specification defines the "application/schema-instance+json"
- media type in order to allow instance authors to take full advantage
- of parameters and fragment identifiers for these purposes.
-
-
-
Two JSON instances are said to be equal if and only if they are of the same type
@@ -288,6 +278,22 @@
zeros) are insignificant.
+
+
+
+ It is possible to use JSON Schema with a superset of the JSON Schema data model,
+ where an instance may be outside any of the six JSON data types.
+
+
+ In this case, annotations still apply; but validation keywords will not be useful,
+ as they will always pass or always fail.
+
+
+ A custom vocabulary may define support for a superset of the core data model.
+ The schema itself may only be expressible in this superset;
+ for example, to make use of the "const" keyword.
+
+