What is the purpose of DelegateExecute registry value

Question

When reading through the registry shell/open keys, for instance:

HKCU\Software\Classes\ms-settings\shell\open
HKCU\Software\Classes\http\shell\open

I see the Default key which corresponds to the opening application and the way parameters are passed when it is executed.

Sometimes another value of DelegateExecute is also present. What is this value responsible for? Also IsolatedComma is unclear to me.

What are those keys responsible for?