date_views_argument_handler::default_actions in core/modules/date/views/date_views_argument_handler.inc
Provide a list of default behaviors for this argument if the argument is not present.
views_handler_argument_comment_user_uid::default_actions in core/modules/comment/views/views_handler_argument_comment_user_uid.inc
Provide a list of default behaviors for this argument if the argument is not present.
views_handler_argument_null::default_actions in core/modules/views/handlers/views_handler_argument_null.inc
Override default_actions() to remove actions that don't make sense for a null argument.
views_handler_argument_term_node_tid_depth::default_actions in core/modules/taxonomy/views/views_handler_argument_term_node_tid_depth.inc
Override default_actions() to remove summary actions.