Server-Pull uses a META-Tag that instructs the client to load a page after a certain amount of time. If the target URL is not given, the same page is reloaded after the amount of seconds specified.
<HEAD> <META HTTP-EQUIV="refresh" CONTENT=time_in_seconds;URL=complete_url"> </HEAD>
Notice that the url to be loaded may not be a relative url. The META-Tag must appear in the HEAD.
Server-pull is particularly suitable when you know ex-ante after how many seconds the screen of the participant should be updated. A Dutch auction, e.g., where prices are constantly decreasing, could reread every two seconds the current page to reveal the current state of the auction.