Mozilla/5.0 (Macintosh; U; PPC Mac OS X; en-us) AppleWebKit/85.7 (KHTML, like Gecko) safari/85.5
(will vary depending on your version of Safari).
You send this string when you select "Automatically Chosen" from the Debug menu, which is the default (ie what is used if the debug menu isn't enabled).
Mozilla/5.0 = Netscape, but that doesn't tell you much because almost all browsers, including Microsoft ones, are based on Netscape. The major exception would be text-only browsers, like Lynx.
Gecko and KHTML are the more important ones; basically telling the site that you're not using Internet Explorer. Safari is essentially the same as FireFox, Netscape, Opera, Konquerer, etc.
Most user agents report the architecture and/or OS you're using.
U, en-us is your language and text encoding preference.
Examples of User Agent strings:
IE6 on Windows NT
Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 1.1.4322)
IE5 on MacOS
Mozilla/4.0 (compatible; MSIE 5.23; Mac_PowerPC)
IE 5.5 on Windows98
Mozilla/4.0 (compatible; MSIE 5.5; Windows 98; Win 9x 4.90)
Thunderbird on Windows NT
Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.5) Gecko/20041206 Thunderbird/1.0
FireFox on Windows NT
Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.6) Gecko/20050225 Firefox/1.0.1
(Search Engine Bots; note: modified so they won't show up as links):
Last edited by gordguide; Mar 8th, 2005 at 01:19 PM.