Readme update

README.md

@@ -16,4 +16,31 @@ To generate the OpenAPI specifications in both YAML and JSON format use the scri
 ```
 . ./api_docs.sh
 ```
-This script employs the openapi.py utility
+This script employs the openapi.py utility
+
+# Style
+
+## Attribute Name
+
+Attribute names refect the UML model for all simple type attributes and all relationships. Where a relationship is turned into a cross reference (so as not to include the content twice in the serialization) either Id or Ids is appended to the attribute name for 1 to 1 or 1 to many relationship respectively. When Id or Ids is appended the root attribute name may be altered so as to make the new name readble, for example the attribute 'children' becomes 'childIds'.
+
+## Attribute Definition
+
+The following coding style is used in attribute definitions. For required simple type attributes the coding convention used is as follows:
+
+Required: ```attributeName: typeName```
+Optional: ```attributeName: typeName = None```
+
+The convention used for relationships and cardinality is as follows
+
+For 1:1: ```attributeName: ClassName```
+For 1:0..1: ```attributeName: Union[ClassName, None] = None```
+For 1:1..*: ```attributeName: [ClassName]```
+For 1:0..*: ```attributeName: [ClassName] = []```
+
+For cross references (note the addition of 'Id' or 'Ids')
+
+For 1:1: ```attributeNameId: str```
+For 1:0..1: ```attributeNameId: Union[str, None] = None```
+For 1:1..*: ```attributeNameIds: [str]```
+For 1:0..*: ```attributeNameIds: [str] = []```