Device type that describes the object. It is a combination of the following flags describing the object type (axis, button, and so forth) and containing the object-instance number in the middle 16 bits. When requesting a data format, the instance portion must be set to DIDFT_ANYINSTANCE to indicate that any instance is permissible, or to DidftMakeinstance(n) to restrict the request to instance n. See the examples under Remarks.
Offset within the data packet where the data for the input source is stored. This value must be a multiple of 4 for DWORD size data, such as axes. It can be byte-aligned for buttons.
Unique identifier for the axis, button, or other input source. When requesting a data format, making this member NULL indicates that any type of object is permissible.