Sometimes it makes sense to have a default value for parameters. This can be done by creating a new file parameters_default.yml (can be any name you like) and adding it to config.yml just before parameters.yml.
imports:
- { resource: parameters_default.yml }
- { resource: parameters.yml }
parameters:
locale: en
secret: abcdefg1234567890
Now you can overwrite the default values in parameters.yml on demand but you’re not longer forced to define those parameters.
parameters:
locale: de