Namespace when setting custom claims

Hi
Here is the login action example,

exports.onExecutePostLogin = async (event, api) => {
  const namespace = 'https://my-app.example.com';
  if (event.authorization) {
    api.idToken.setCustomClaim(`${namespace}/roles`, event.authorization.roles);
    api.accessToken.setCustomClaim(`${namespace}/roles`, event.authorization.roles);
  }
}

Am I correct to assume that the namespace has no relation to the application identifier? What is the appropriate namespace in the case where there are multiple applications with specific roles and permissions?

I found this namespaced guidelines.

I guess we have to decide one “generic” namespace in the case where there are multiple web apps hosted in different domains.