Use the HTTP Headers tab to set values returned to the browser in the header of the HTML page. You can also set content ratings for content, and define MIME types.
These values can be set globally for all sites or separately within each site. Internet Information Services (IIS) uses an inheritance model for these settings. If you set or change a setting that conflicts with a setting at another node in the hierarchy, you are prompted to specify the nodes to which this new setting applies.
Enable content expiration
Select the Enable content expiration check box to include expiration information for time-sensitive material, such as special offers or event announcements. The browser compares the current date to the expiration date to determine whether to display a cached page, or to request an updated page from the server.
Click this option and content expires immediately after it is served. This setting forces the browser to always retrieve the content fresh from the server on subsequent requests.
Set a specific period of time after which the browser is forced to retrieve the content again from the server on the subsequent requests.
Select to set a specific date and time after which the browser is forced to retrieve the content again from the server on the subsequent requests.
Custom HTTP headers
You can use this property to send a custom HTTP header from the Web server to the client browser. Custom headers can be used to send instructions from the Web server to the client browser that are not yet supported in the current HTTP specification, such as newer HTTP headers that IIS may not inherently support at the time of the product's release. For example, you can use a custom HTTP header to allow the client browser to cache the page but prevent proxy servers from caching the page.
Click to add a new custom HTTP header.
Click to edit the properties of the currently selected custom HTTP header.
Click to remove the currently selected custom HTTP header.
Use content ratings to embed descriptive labels in the HTTP headers of your Web pages. Some browsers can detect content ratings to help users identify potentially objectionable Web content.
Click to set content rating values.
MIME types (site, directory, and virtual directory levels)
Multipurpose Internet Mail Extensions (MIME) mappings set the various file types that IIS serves to clients. IIS serves only files with extensions registered in the MIME types list.
MIME types can be defined globally for IIS, and additional MIME types can be defined at the Web site, Web site directory, and Web site virtual directory level.
IIS uses an inheritance model for MIME type settings. MIME types defined at the global level are inherited by all Web sites, Web site directories, and Web site virtual directories. MIME types defined at the Web site, Web site directory, or Web site virtual directory are used only at that particular node. If you set or change a MIME type that conflicts with a setting at another node in the hierarchy, you are prompted with an Inheritance Override dialog box where you can specify the nodes to which the new setting applies.
The registered file types that are installed on this computer are listed in the Registered MIME types (file extensions) list box.
IIS 6.0 returns an error (404.3) if a request refers to a file with a file name extension that is not in the MIME mapping or script mapping. To remedy the 404.3 error, you must add the requested file name extension to the MIME mapping. Click MIME Types on the open dialog box to configure MIME mappings.
Click to configure MIME mappings. These mappings set the various file types that the Web service returns to browsers.
When you click a MIME type, the MIME mappings are listed in the MIME Types box.
To learn more about content ratings and MIME types, see the