This screen is part of a Web Feed Reference section for the Web Feed Generator. Please ask us if you cannot find the answer to your question.
Methods vary according to the server software you use and you should ask whoever manages your Web server to check the manual and make these changes for you. Guidance for the two most popular servers is listed below.
Normally, you can set your page to expire a number of minutes, hours or days after someone first requests it. The interval you choose is a balance between how often you update your page and how quickly you would like people to know there is something new.