Header Informer
header-informer.php is a tool installed on a webserver used to gain insight on a server's view point of what information is available when a page request is made or data is transferred to the server via POST or GET methods. The tool is an all-in-one html-css-php file because web-2.0-ifying the tool would add uncessary complexity. I use this tool for troubleshooting and illustrating server issues.
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