The specification for BaseStream.iterator() is silent about the order in which it produces elements. This is contrary to the intent, which is that if the stream has a defined encounter order, the iterator produces elements in encounter order. This is most likely simply an oversight. The specification should be updated.

It may also be useful to scan various overview specs and the specs for the intermediate and terminal ops to see if the issue of ordering is adequately covered. In principle this ought to be done for all the stream (spliterator) characteristics, but ordering is probably the one that's most relevant to applications.