Example routing setup for the "Flickr" Plugin of the TYPO3.NeosDemoTypo3Org package

Routes.yaml

-
  name: 'Flickr: User stream'
  uriPattern: '{node}/user/{--typo3_neosdemotypo3org-flickr.userId}.html'
  defaults:
    '@package':    'TYPO3.Neos'
    '@controller': 'Frontend\Node'
    '@action':     'show'
    '@format':     'html'
    '--typo3_neosdemotypo3org-flickr':
      '@package':    'TYPO3.NeosDemoTypo3Org'
      '@controller': 'Flickr'
      '@action':     'userstream'
  routeParts:
    'node':
      handler:     'TYPO3\Neos\Routing\FrontendNodeRoutePartHandlerInterface'
    '--typo3_neosdemotypo3org-flickr.userId':
      toLowerCase: false

-
  # This is only added so that the back link from the user stream does not contain the plugin arguments
  name: 'Flickr: Tag stream'
  uriPattern: '{node}.html'
  defaults:
    '@package':    'TYPO3.Neos'
    '@controller': 'Frontend\Node'
    '@action':     'show'
    '@format':     'html'
    '--typo3_neosdemotypo3org-flickr':
      '@package':    'TYPO3.NeosDemoTypo3Org'
      '@subpackage': ''
      '@controller': 'Flickr'
      '@action':     'tagstream'
  routeParts:
    'node':
      handler:     'TYPO3\Neos\Routing\FrontendNodeRoutePartHandlerInterface'

Include this before the default neos routes

Remove ".html" from the uriPatterns if that's your preferred URI scheme