For the following element: -

<element name='lookup'>
<complexType>
<sequence>
<element name='Details'>
<complexType>
<sequence>
<element name='Name'>
<complexType>
<sequence>
<element name='firstName' nillable='true' type='string'/>
<element name='surname' nillable='true' type='string'/>
</sequence>
</complexType>
</element>
</sequence>
</complexType>
</element>
</sequence>
</complexType>
</element>

Classes will be created called 'Lookup', 'LookupDetails' and 'LookupName', however within the JAX-RPC mapping the final class will be mapped as 'DetailsName'.