For those of you smart enough to own a copy of XQuery by Priscilla Walmsley, it was updated as of 15 September 2017.
There’s a four (4) page difference in length between the original edition (758 pages) and the updated version (762 pages).
One two (2) page addition is the new section “Specifying Serialization Parameters by Using a Map” plus an unnecessary page break following the introduction to example 13-4 (of the updated version).
Chapter 13, Inputs and Outputs, now ends on page 228 instead of 226.
The other two pages arise from the insertion of array:put following prefix-from-QName and before map:put, in Appendix A. Built-in Function Reference.
I haven’t found any mention of the pagination difference, which will be confusing for students consulting Walmsley.
Since the edition is not being updated, putting the added four pages in an Appendix D or even in preface material numbered i, ii, …, would have preserved references across the first and second versions.
XQuery should be widely used. Creating unnecessary friction for using XQuery resources doesn’t advance that goal.