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- Default values entered when the form was created in the Form Designer
- Values from an XML document(s) sent in the Post request for the form or OnInit.
- URL parameters appended to the form URL via the _data URL parameter
- Values retrieved as the form loads from any Document URIs
- And finally default values set via Business Rules as the form loads and during use. See Setting default values in rules and using REST Services in Rules for further details.
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See default field values to understand the precedence that XML documents sent in the Post request to form B take over the other possible methods of defaulting form field values.
See Initializing Forms with XML Documents for more information.