name or category from WSDL used for SOAP tag name?

Hi all,

i'm currently evaluating soapUI to automate some SOAP API tests. I imported a WSDL file and started to create some tests. One element is described at the WSDL like:

<xs:element name="create">
  <xs:complexType>
    <xs:sequence>
      <xs:element minOccurs="0" name="ctx" nillable="true" type="ax248:Context"/>
      <xs:element minOccurs="0" name="admin_user" nillable="true" type="ax248:User"/>
      <xs:element minOccurs="0" name="auth" nillable="true" type="ax248:Credentials"/>
    </xs:sequence>
  </xs:complexType>
</xs:element>

soapUI generates a request based on the WSDL like this:

  <soap1:auth>
    <xsd:login xmlns:xsd="http://dataobjects.example.com/xsd">adminuser</xsd:login>
    <xsd:password xmlns:xsd="http://dataobjects.example.com/xsd">secret</xsd:password>
  </soap1:auth>

Is there any reason why "auth" as tag name is used? Is it specified anywhere that the "name" from the WSDL needs must be used for that? A guy i asked about that replied that the "category" value from the WSDL must be used for the tag name.

Thanks!
Martin