When invoking a sub-activity using startActivityForResult(), one uses the setResult() method, its first parameter being either RESULT_OK or RESULT_CANCELLED. I have seen other upper-case 'things' used as well. What are these 'things'? What data type are they? Is there a list somewhere? I've tried looking them up in various reference documents, with no success. Thanks for your help.
The first parameter of the Activity.setResult method is an int.
Is there a list somewhere?
No, because users can define their own result codes. Quoting the Activity javadoc:
When an activity exits, it can call setResult(int) to return data back to its parent. It must always supply a result code, which can be the standard results RESULT_CANCELED, RESULT_OK, or any custom values starting at RESULT_FIRST_USER.