This encoding header tells a web server to send gzip content if available.
'accept-encoding': 'gzip,deflate,sdch',
How can I instruct the web server to send plain text and not gzip the content? I am aware that the web server can simply ignore this request if it wanted to.
Leaving the encoding out of accept-encoding will disallow that encoding (ie gzip).
If you want to explicitly set it as disallowed, you can set a qvalue
of 0.
'accept-encoding': 'gzip;q=0,deflate,sdch'
You can read more under accept-encoding in RFC2616, but in short if the server can't find an acceptable encoding among the ones listed (identity being a special case, see the link), it should send a 406 (Not Acceptable) response and not reply to your request with any other encoding.