  We show how to use a balanced wavelet tree as a data structure that stores a
list of numbers and supports efficient {\em range quantile queries}. A range
quantile query takes a rank and the endpoints of a sublist and returns the
number with that rank in that sublist. For example, if the rank is half the
sublist's length, then the query returns the sublist's median. We also show how
these queries can be used to support space-efficient {\em coloured range
reporting} and {\em document listing}.
