For use when building custom links in the ZMS backend (normally for non-admin users). For example when making direct links to edit Feature content, unless you add "&lastaction=home" to the end of your custom link, when the user clicks the back button they will end up in the Featuresstyle overview.
Example of use in admin_main.php:
'Projektmanagement' => $_SERVER['SCRIPT_NAME'].'?pid='.UTIL_FILTER::URLEnc(PAGE_ADMINFEATUREEDIT).'&fsid='.UTIL_FILTER::URLEnc
(FS_SIMPLECONTENTCONTROLLER).'&fid=11&lastaction=home',