Hi, The StructTreeRoot dictionary must have a ParentTree entry whose type is a number tree. As explained in Section 3.8.5, “Number Trees” of the PDF Reference, Third Edition, the Nums entry of a number tree node must be an array of key-value pairs where value is an indirect reference to the object associated with the key.
This is not what is done in the current implementation of Logical Structure in FOP (Temp_Accessibility branch). The value (an array) is directly stored in the array of key-value pairs instead of being referenced. So technically the PDF produced is invalid. Acrobat doesn’t seem to complain, though. Did I miss anything? Thanks, Vincent