There are 2 integrated functions which can be used to advertise your TeamSpeak server to the public. One of them is the public "Web Server List" which is available in every TeamSpeak client. The other feature is called "Webpost" and can be used to report your server stats to a 3rd party PHP script (i.e. gllcTS2 WebPost).

You can modify the settings for these features in the "Global settings" section of the web administration interface.
The first 4 settings are public information about your server which can be requested by anyone on the world who has access to your servers TCP query port. They will also show up on Webpost pages and some are also beeing used for the Web Server List.
The other options are related to the according feature.
Web Server List settings
Please note
If you enter a "WebPost PostURL" here, all virtual servers of this TeamSpeak installation will be posted to that Webpost. Each virtual server has an aditional "WebPost PostURL" and a corresponding "Server WebPost LinkUrl" setting. The last one is the same like the "ISPLinkURL" with the difference that it is only valid for the Webpost function of this specific virtual server.