You just can't. Customer is not interested in you Service Code. It only cares about the endpoint (abc-address, binding, contract). Remember that you do not call the code, you send a message through the wire (or between processes), which will be received and translated to use your code.
client - call service (via through code friendly proxy) - create message - serialise - send service - receive message - validate/verify - deserialise - authenticate/authorise - call friendly code with friendly content
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