I want to add a Custom field to the ContactsContract content provider. I'm trying to build a Voip application and would like to add a SIP address(name@domain) field to it. What MIME type will I need to associate with it? Also I want to add a group address field which will have a list of group addresses in it (name@domain, name@domain,...). Wich MIME type will I have to associate with this type of field. I also want to add custom fields to the Call History like a session ID and SIP address(name@domain) field. How can I customize the call history? It'll be great if someone can give me an example.