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README.md

@@ -54,16 +54,16 @@ properties that may or may not be present.  For example:
 ```python
 someJSON.get("thing", {}).get("subThing", None)
 if subThing is not None:
-   ...
+   ... # "thing" or "subThing" not present
 ```
 
-What is less easy is guarding against properties being present with the wrong type.  For example:
+What is less easy is guarding against properties being present with the wrong type.  For example, if `thing` is a list:
 
 ```python
 json.loads('{"thing": [ ] }').get("thing", {}).get("subThing", None)
 ```
 
-Gives:
+We get:
 
 ```
 AttributeError: 'list' object has no attribute 'get'
@@ -76,6 +76,12 @@ readable than doing type checks manually in code.
 Short JSON Schema is intended to allow concise specification of JSON formats,
 so that your code needn't be cluttered with checks for the correct structure.
 
+## Scope
+
+Short JSON Schema supports a subset of JSON Schema functionality.  The
+`shortjsonschema` Python module converts Short JSON Schema syntax into standard
+JSON Schema.
+
 ## Defaults
 
 In Short JSON Schema, properties are required by default, and additional