xmlns:SOAP-ENC, xmlns:xsd required?

[chris.stromberger]

New to SOAP. I am working on something that uses the paypal web
services. All the examples have this as the first portion of the soap
doc

<?xml version="1.0" encoding="UTF-8"?>
<SOAP-ENV:Envelope
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:SOAP-ENC="http://schemas.xmlsoap.org/soap/encoding/"
xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/"
xmlns:xsd="http://www.w3.org/2001/XMLSchema"
SOAP-ENV:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">
<SOAP-ENV:Header>
<RequesterCredentials
xmlns="urn:ebay:api:PayPalAPI"
SOAP-ENV:mustUnderstand="1">
<Credentials xmlns="urn:ebay:apis:eBLBaseComponents">
<Username>...</Username>
<Password>...</Password>
<Subject/>
</Credentials>
</RequesterCredentials>
</SOAP-ENV:Header>

I'm wondering if the xmlns:SOAP-ENC attribute is needed. "SOAP-ENC:"
is not used anywhere in the document. From my vague understanding of
xml namespaces, the
xmlns:SOAP-ENC="http://schemas.xmlsoap.org/soap/encoding/" attribute
then serves no purpose (and it seems to be sort of repeated in the
SOAP-ENV:encodingStyle attribute also???). I'm just not sure if it has
to be there for some mysterious SOAP reason.

Ditto for the xmlns:xsd attribute--the xsd prefix is not used anywhere
else in the document. Is it required for some SOAP reason?

Thanks,
Chris