You can do more elaborate grouping by setting up $cache_id groups. This is accomplished by separating each sub-group with a vertical bar | in the $cache_id value. You can have as many sub-groups as you like. You can think of cache groups like a directory hierarchy. For instance, a cache group of 'a|b|c' could be thought of as the directory structure '/a/b/c/'. clear_cache(null,'a|b|c') would be like removing the files '/a/b/c/*'. clear_cache(null,'a|b') would be like removing the files '/a/b/*'. If you specify a $compile_id such as clear_cache(null,'a|b','foo') it is treated as an appended cache group '/a/b/c/foo/'. If you specify a template name such as clear_cache('foo.tpl','a|b|c') then Smarty will attempt to remove '/a/b/c/foo.tpl'. You CANNOT remove a specified template name under multiple cache groups such as '/a/b/*/foo.tpl', the cache grouping works left-to-right ONLY. You will need to group your templates under a single cache group heirarchy to be able to clear them as a group. Cache grouping should not be confused with your template directory heirarchy, the cache grouping has no knowledge of how your templates are structured. So for example, if you have a template structure like themes/blue/index.tpl and you want to be able to clear all the cache files for the blue theme, you will need to create a cache group structure that mimics your template file structure, such as display('themes/blue/index.tpl','themes|blue'), then clear them with clear_cache(null,'themes|blue'). caching = true; // clear all caches with 'sports|basketball' as the first two cache_id groups $smarty->clear_cache(null,'sports|basketball'); // clear all caches with "sports" as the first cache_id group. This would // include "sports|basketball", or "sports|(anything)|(anything)|(anything)|..." $smarty->clear_cache(null,'sports'); // clear the foo.tpl cache file with "sports|basketball" as the cache_id $smarty->clear_cache('foo.tpl','sports|basketball'); $smarty->display('index.tpl','sports|basketball'); ?> ]]>