Control caching on pages created dynamically, for example, search results. Extremely obsolete, it is used for compatibility with old equipment and software running with the HTTP / 1.0 protocol. Until now include the very "every" case, that somewhere, on intermediate routers or proxy servers, there is an ancient software or hardware. In modern conditions, when using encrypted connections, SSL / TLS loses all meaning. Also almost useless in the body of the page for intermediate devices.
Almost the same as the HTTP header Cache-Control: no-cache or <meta http-equiv="Cache-Control" content="no-cache"/>.
< meta http-equiv = "Pragma" content = "no-cache" >