We don't use it and it uses ( for opening parenthesis.
I am not sure whether this has some reason or not, but
we want to get reed of &#xx; chars in our change to utf-8,
so easier to remove than to find out why...
By default page numbering in <preface> is in roman numeral. This
is ok for the book preface, but not for the part III preface.
So copy the page.number.format template from docbook stylesheets
to stylesheets/lfs-xsl/pdf/lfs-pagesetup.xsl, and modify it.
Reported by: Vladimir Pertsev on lfs-dev list