Subuserid: Sub-user id can be a unique ID or number or company name. Suppose if you have so many users, you can save each user based on the Unique id such as User1, User2, User3, etc....
Subuserid can be set different for Staging environment and different for Production one. It can be "Staging_8.0.0" for testing or staging application and "Production_8.0.0" for a production application.
You can change the Subuserid anytime from your end, but please always share it with the RChilli Team.
Subuserid should always be different for each user and can be used for the categorization of your users.