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

Rails
1

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

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