Correct status code for unknown transfer-encoding

Hi,

over on stackoverflow.com, somebody asked for the right status code to 
return when the request has a TE: header with an unknown transfer coding 
[1].

The answer is not obvious; is this a client or a server error? Should 
the specification say something about this?

BR, Julian

[1] 
<http://stackoverflow.com/questions/692910/http-transfer-encoding-and-requests>