HTTP RFC 2616 Question

In section 5.1 of RFC 2616 (
http://www.w3.org/Protocols/rfc2616/rfc2616-sec5.html#sec5.1
<http://www.w3.org/Protocols/rfc2616/rfc2616-sec5.html#sec5.1> ), the line
for an HTTP PUT command specifies that HTTP/1.1 be appended to the end of
the command. Would a web server platform that does not support the
HTTP-version append be out of compliance with the RFC, or is this an
optional command for older web server platforms?
 
 
Thanks in advance!
 
Dean Cron