--- /dev/null
+HTML.DefinitionID\r
+TYPE: string/null\r
+DEFAULT: NULL\r
+VERSION: 2.0.0\r
+--DESCRIPTION--\r
+\r
+<p>\r
+ Unique identifier for a custom-built HTML definition. If you edit\r
+ the raw version of the HTMLDefinition, introducing changes that the\r
+ configuration object does not reflect, you must specify this variable.\r
+ If you change your custom edits, you should change this directive, or\r
+ clear your cache. Example:\r
+</p>\r
+<pre>\r
+$config = HTMLPurifier_Config::createDefault();\r
+$config->set('HTML', 'DefinitionID', '1');\r
+$def = $config->getHTMLDefinition();\r
+$def->addAttribute('a', 'tabindex', 'Number');\r
+</pre>\r
+<p>\r
+ In the above example, the configuration is still at the defaults, but\r
+ using the advanced API, an extra attribute has been added. The\r
+ configuration object normally has no way of knowing that this change\r
+ has taken place, so it needs an extra directive: %HTML.DefinitionID.\r
+ If someone else attempts to use the default configuration, these two\r
+ pieces of code will not clobber each other in the cache, since one has\r
+ an extra directive attached to it.\r
+</p>\r
+<p>\r
+ You <em>must</em> specify a value to this directive to use the\r
+ advanced API features.\r
+</p>\r
+--# vim: et sw=4 sts=4\r