Characters before doctype and after html tag viewed by rexswain http sniffer

Question

Most of websites when shown with the http://www.rexswain.com/httpview.html viewer display some extra characters before the DOCTYPE and also after the ending HTML tag. Is this really sent by the server or it's a bug of the rexswain viewer ?

EDIT: For example, the first 2 lines of drupalfrance.com are

7add(CR)(LF)
<!DOCTYPE·html·PUBLIC·"-//W3C//DTD·XHTML+RDFa·1.0//EN"(LF)

and the 4 last lines are

</html>(LF)
(CR)(LF)
0(CR)(LF)
(CR)(LF)

Answer 1

In the HTTP header, notice Transfer Encoding: chunked.

The hexadecimal number (followed by CR,LF) is the number of characters in the following chunk. In your case, 7add = 31453. Then 0,CR,LF indicates the end.