edlp_d8/core/modules/system/system.links.task.yml

system.rss_feeds_settings_tab:
  route_name: system.rss_feeds_settings
  title: Settings
  base_route: system.rss_feeds_settings

system.site_maintenance_mode_tab:
  route_name: system.site_maintenance_mode
  title: Settings
  base_route: system.site_maintenance_mode

system.site_information_settings_tab:
  route_name: system.site_information_settings
  title: Settings
  base_route: system.site_information_settings

system.themes_page:
  route_name: system.themes_page
  title: 'List'
  base_route: system.themes_page
system.theme_settings:
  route_name: system.theme_settings
  title: 'Settings'
  base_route: system.themes_page
  weight: 100

system.theme_settings_global:
  route_name: system.theme_settings
  title: 'Global settings'
  parent_id: system.theme_settings
  weight: -100
system.theme_settings_theme:
  route_name: system.theme_settings_theme
  title: 'Theme name'
  parent_id: system.theme_settings
  deriver: Drupal\system\Plugin\Derivative\ThemeLocalTask

system.modules_list:
  route_name: system.modules_list
  base_route: system.modules_list
  title: 'List'
system.modules_uninstall:
  route_name: system.modules_uninstall
  base_route: system.modules_list
  title: 'Uninstall'
  weight: 20

system.admin:
  route_name: system.admin
  base_route: system.admin
  title: 'Tasks'
  weight: -20
system.admin_index:
  route_name: system.admin_index
  base_route: system.admin
  title: 'Index'
  weight: -18

entity.date_format.collection:
  route_name: entity.date_format.collection
  base_route: entity.date_format.collection
  title: 'List'
entity.date_format.edit_form:
  title: 'Edit'
  route_name: entity.date_format.edit_form
  base_route: entity.date_format.edit_form

system.admin_content:
  title: Content
  route_name: system.admin_content
  base_route: system.admin_content

system.performance_settings:
  title: 'Performance'
  route_name: system.performance_settings
  base_route: system.performance_settings