This article describes how to prevent your web site from sending entity tags (ETags) in the HTTP headers.
Entity tags (ETags) are used in HTTP headers to manage web caching behavior. They provide a way for web clients to determine if their cache content matches the content on the web server. If the entity tags for a particular resource (such as an image file) do not match, the web client sends a request to the server to download the most recent version.
By default, entity tags are enabled on your hosting account. However, there may be scenarios where you do not want to send entity tag headers. For example, you might want to disable entity tags during site development or to test web caching.
To disable sending entity tags in the HTTP headers, add the following two lines to an .htaccess file in your account's public_html directory:
Header unset ETag FileETag None
The changes take effect immediately. To re-enable entity tags, comment out or delete the two lines in the .htaccess file.
For more information about the FileETag directive, please visit https://httpd.apache.org/docs/2.2/mod/core.html#fileetag.