The following-sibling axis selects elements that follow the
context node in the same parent element. For example,
/descendant::BORN[position()=2]/following-sibling::*[position()=1]
selects Elodie Bellau's DIED element, <DIED>12 Apr
1898</DIED>. /descendant::BORN[position()=2]/following-
sibling::*[position()=3] doesn't point to anything because there are only
two sibling elements following Elodie Bellau's BORN element.
There's no abbreviation for the following-sibling axis.