CRM 1:N relationships that are “Configurable cascading” type allow you to customize several cascading behaviors. For example, in the system parental relationship between Accounts and Contacts, you can change the relationship type to “Configurable Cascading” and then set the “Share” permission cascading to “Cascade None” so that sharing an Account with George will not also share the related contacts.
The most misunderstood cascading permission is “reparent.” My experience is that if you ask five CRM configurators what “reparent” means, at least two will probably think that is reassigning the account.
Reparenting is changing the parent in the relationship. For example, if I have contact where the parent customer is Fabrikam and I change the parent customer lookup to Contoso, with the default reparent cascading, the owner of Contoso will now have access to the contact.
By setting the cascading setting for “reparent” to “Cascade None,” the owner of the new parent will not be granted access to the record when the parent is changed.