ZF-4698: WSDL does not support soap:header tags
Binding Operations allow to specifiy tags beneath the in both and . This is currently not supported by Zend_Soap_Wsdl.
For this to work properly Zend_Soap_Wsdl should be refactored big time, its currently implemented quite slobbish and hardcoded in its XML building.
As a hack, though this is probably not desired, one could extend the addBindingOperation() function to take another parameter $soapHeaders with 'input', 'output' keys in the first level and key->params that map to attribute name and value in the second level.