7 string references to 'rule'

hook_rules_plugin_info in ./rules.api.php: Defines rules plugins.
rules_drush_command in ./rules.drush.inc: Implements hook_drush_command().
rules_rules_plugin_info in ./rules.module: Implements hook_rules_plugin_info().
rules_upgrade_convert_element in includes/rules.upgrade.inc: Convert a single element.
rules_upgrade_convert_rule_set in includes/rules.upgrade.inc: Converts a single rule set, including all of its rules.
rules_upgrade_form_submit in includes/rules.upgrade.inc: Submit handler for the form.
rules_upgrade_plugin_factory in includes/rules.upgrade.inc: Creates the right element.