The mp2 parameter of this message points to a BOOKPAGEINFO data structure. The pBidiInfo field in this data structure points to the BOOKPAGEBIDIINFO structure.
The "fl" field of the BOOKPAGEINFO structure must have the BFA_BIDIINFO flag set to indicate that Bidi Attributes of the MajorTab/MinorTab/Status line text (as indicated by the other flags in the "fl" field) are queried.