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You can check that the meta tag is visible by viewing your site’s HTML source and searching for “GNU Terry Pratchett”. To send the HTTP header and continue to use a caching plugin, add the header at the server level. Note that the HTTP header is not sent if you use a page caching plugin.
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This plugin makes it easy for WordPress users to do the same for Terry Pratchett, without having to modify their server configuration.
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In Pratchett’s “Going Postal”, workers who die in the line of duty have their names transmitted up and down the Discworld’s telegraph system as a tribute. The GNU Terry Pratchett plugin transmits an “X-Clacks-Overhead” header reading, “GNU Terry Pratchett” so that Terry’s name is whispered forevermore in the Internet’s “overhead”.
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