Main_Routes.yaml

#This walks into the main Routes.yaml in Flows Root Folder "Configuration"

-
  name: 'Your Fantastic Name'
  uriPattern: '<YourPackageSubroutes>'
  subRoutes:
    'YourPackageSubroutes':
      package: 'YOUR.Package'

Routes.Registration.yaml

# This will contain your detailes routing for your controller "Registration" f.e. Its located in "Your.Package/Configuration"
# The defaults from the Routes.yaml (f.e. @action) will be overwritten here and getting the pattern "signup/do" instead of "your.package/create"

-
  name: 'Sign up'
  uriPattern: 'sign-up'

-
  name: 'Registration'
  uriPattern: 'sign-up/do'
  defaults:
    '@action': 'create'
  appendExceedingArguments: TRUE

Routes.yaml

# This walks into you Package Routes.yaml of your package. it works as a "wrapper" wich uses, in this example, the file "Routes.Registration.yaml" wich is located next to "Routes.yaml" in the folder "Your.Package/Configuration"

-
  name:  'RegistrationController'
  uriPattern: '<RegistrationSubRoutes>'
  defaults:
    '@package':    'YOUR.Package'
    '@controller': 'Registration'
    '@action':     'index'
    '@format':     'html'
  subRoutes:
    'RegistrationSubRoutes':
      package: 'YOUR.Package'
      suffix:  'Registration'