\$cache\_modified\_check {#variable.cache.modified.check} ======================== If set to TRUE, Smarty will respect the If-Modified-Since header sent from the client. If the cached file timestamp has not changed since the last visit, then a `'304: Not Modified'` header will be sent instead of the content. This works only on cached content without [`{insert}`](#language.function.insert) tags. See also [`$caching`](#variable.caching), [`$cache_lifetime`](#variable.cache.lifetime), and the [caching section](#caching).