PluginResponseInfo exists to be able to respond with more than just a true/false, but also an explanation. Such an explanation can be displayed on for instance a disabled Place Order button.
Answer to the question / An indication of whether the operation went well.
A localized explanation to the answer. Example: US:"Text in English"; NO:"Text in Norwegian"; GE:"Text in German": FR:"Text in French"; and so on
Always in English
An error code, if available.