1. Handling of undefined content-type
doesn't expect a URL's response without content-type. And if it happens, the following message is shown: "Error: Unsuported content type: %PARAM1%". According to RFC2616, undefined content-type should be treated as application/octet-stream.
2. Specifying charset
You may want to specify charset of INCLUDE'd content when 1) charset is not provided; 2) provided charset needs to be overridden.
As such, the
parameter needs to be introduced to