In the <wsdl>binding> element, there are, among others, the following elements:
Used to specify the encoding style for the body of ingoing and outgoing messages of an operation.
Used to specify the encoding style for a fault.
Used to specify the encoding style for SOAP headers.
Used to specify the encoding style for a header fault.
All the above are pretty much obsolete (but must still be specified ), since the only recommended encoding is literal encoding.
If you haven't already, take a look at section 2.1 in my study notes. In case of further doubts, please do not hesitate to ask again!