(non hot-linked) olink reference to book in PDF format

Hi,

I'm trying to link between books (without hot-links).

The text that is generated for everything but the top-level books is fine. It renders Refer to <olink targetdoc="bookDocId" targetptr="section"/> as Refer to Section x,y, “Title” in Book Title.

But when I olink to the book itself: Refer to <olink targetdoc="bookDocId" targetptr="bookId"> there is no fo:inline element, it just renders the book title: Refer to Book Title.

Is there some configuration or customisation that I can do to get this to render as something like Refer to Document "Book Title".

I'm using docbkx 2.0.15 which uses version 1.78.1 of the stylesheets.

Nat