Arguments create a context from external input, which is assumed to be a string as though it came from a URL element. 'title' => title 'description' => Description 'keyword' => Default keyword for the context 'context' => Callback to create the context. Params: $arg = NULL, $conf = NULL, $empty = FALSE 'settings form' => params: $conf 'settings form validate' => params: $form, $form_state 'settings form submit' => params: $form, $form_state