Namespace declarations in XML

Good day, all!

This question could be related to a misunderstanding on my part, but everything I've looked at today, and every piece of XML I've ever worked with tells me otherwise.

I have a client passing me a feed with a top-level element that looks like this:

<ArrayOfProductType xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://catalog.9squared.com">

Now, am I mistaken in thinking that namespace declarations are inappropriate in an XML feed? And if I am mistaken, how do I work with that? I even duplicated these namespace declarations in my xsl and then pointed them to resolve to the xsl namespace, but I am still getting nothing to output.

Any help with this is greatly appreciated... I feel really silly even asking a question like this because I can't believe I've never run into it in almost 8 years working with external clients' XML feeds. So thank you for your gentleness... :)

Cynthia