I have made a VF page and redirected the new button functionality into that VF page. The related SObject is List__c and it has a parent object called Folder__c. And in folder__c page layout I have the list__c related lists. And there is a new list button there.
By clicking that new list button, I realize the page is redirecting to this URL:
In this, CF00N2800000CopEM_lkid seems to be the id of the folder. However, it doesn't seem to be the parameter name is something I can rely on. Seems to me it can change once the package is deployed into another org. So how can I retrieve the parent Id here?