The mapping specification object diagrams show the complete set of object instances and attributes in the named object dictionary that define feature layers and a coordinate system. feature attributes are stored in the Extension dictionary in a similar structure.
Feature layers and coordinate system
![Feature classes and coordinate system Feature classes and coordinate system](GUID-26B954A9-E9B2-426C-B6EA-0768869C1C75-web.png)
Feature attributes
![Feature attributes Feature attributes](GUID-CBEDA863-4ABD-46AF-81C1-21AE52792BBB-web.png)