what is the use of the type information in the serialized xml

hi, i had a general question, what is the use of the type information in the serialized xml?

<?xml version="1.0" encoding="UTF-8"?> <posts type="array"> <post></post> <post></post> </posts

what is the use of saying that posts is of type 'array', any use to ActiveRecord or ActiveResource? would it be useful in deserialization?

PS: ActiveRecord::Base::to_xml has a :skip_types option.

Thanks, Deepak