I have a plugin that sets it TRUE (optimizeMember)
* Defines no-cache constants for various WordPress plugins.
*
* This is compatible with Quick Cache, W3 Total Cache, and also with WP Super Cache.
* Quick Cache uses: <code></code>QUICK_CACHE_ALLOWED<code></code>, and other plugins use: <code></code>DONOTCACHEPAGE<code></code>.
* W3 Total Cache is also known to be compatible with <code></code>DONOTCACHEOBJECT<code></code> and <code></code>DONOTCACHEDB<code></code>.
*
* Disallow caching if the <code></code>$no_cache<code></code> parameter is passed in as <code></code>true<code></code>, by other routines.
* In addition, always disallow caching for logged in users, and GET requests with: <code>/?s2member</code> Systematics.
* For clarity on optimizeMember Systematics, see: {@link optimizeMember\Systematics\c_ws_plugin__optimizemember_systematics::is_s2_systematic_use_page()}.
*
* However, this routine will ALWAYS obey the <code>?qcAC</code> query string parameter.
* This Quick Cache parameter explicitly allows caching to occur.
*
* @package optimizeMember\No_Cache