Someone really could believe so, but the namespace prefixes are not part of the standards. We really recommend you to use a XML parser and a XPath engine. That will allow you to use your own prefixes.
RFC 5730 Section 2 clearly states:
“EPP uses XML namespaces to provide an extensible object management framework and to identify schemas required for XML instance parsing and validation. These namespaces and schema definitions are used to identify both the base protocol schema and the schemas for managed objects. The XML namespace prefixes used in examples (such as the string "foo" in "xmlns:foo") are solely for illustrative purposes. A conforming implementation MUST NOT require the use of these or any other specific namespace prefixes.”