curl empty user agent

gistfile1.txt

→ curl -iI -v -A " " "http://www.la-grange.net/"
* About to connect() to www.la-grange.net port 80 (#0)
*   Trying 128.30.54.58... connected
* Connected to www.la-grange.net (128.30.54.58) port 80 (#0)
> HEAD / HTTP/1.1
> User-Agent:  
> Host: www.la-grange.net
> Accept: */*
> 
< HTTP/1.1 200 OK
HTTP/1.1 200 OK
< Date: Wed, 11 Apr 2012 17:04:24 GMT
Date: Wed, 11 Apr 2012 17:04:24 GMT
< Server: Apache
Server: Apache
< Last-Modified: Thu, 02 Feb 2012 04:46:07 GMT
Last-Modified: Thu, 02 Feb 2012 04:46:07 GMT
< Accept-Ranges: bytes
Accept-Ranges: bytes
< Content-Length: 1162
Content-Length: 1162
< Expires: Wed, 18 Apr 2012 17:04:24 GMT
Expires: Wed, 18 Apr 2012 17:04:24 GMT
< Vary: Accept-Encoding
Vary: Accept-Encoding
< Content-Type: text/html; charset=utf-8
Content-Type: text/html; charset=utf-8

< 
* Connection #0 to host www.la-grange.net left intact
* Closing connection #0