Is it possible to create a new field on Self-Service form such as Personal Details Demographic Info

Summary

Is it possible to create a new field on Self-Service form such as Personal Details Demographic Info that will be viewable and update able as an employee and HR

Content

Hi All-

Is it possible to create a new field on Self-Service form such as Personal Details Demographic Info that will be viewable and update able as an employee and HR?

If so, do you have any good document references to complete this?  That was just an example, I would like to know in general if you can create your own custom field in Self-Service and then have it update a field that you have created in HR.