Should variables go to provider or custom section in serverless.yml?

I want to declare a variable in serverless.yml like this threshold: 10. Should i put it in provider or custom section?

Threshold: ${self:custom.threshold}

Seem to me both sections should work, but what is the standard or best practices?

Besides, what should go into provider section? I can’t really find any documentation about that. I read through but it doesn’t have talk about that.

Put it in the custom section. Use the provider section for provider specific settings for Serverless. If you start putting custom settings in the provider section you may end up with a rude surprise one day if the key you’re using suddenly means something.

I’m not aware of a complete list of provider specific settings.

Thanks for your great response.