NSIncludesSubdomains
A Boolean value that indicates whether to extend the configuration to subdomains of the given domain.
Discussion
You can include this key in any of the domain-specific dictionaries that you add to the NSExceptionDomains and NSPinnedDomains dictionaries. Adding the NSIncludesSubdomains key affects the applicability of the other configuration in the same domain-specific dictionary. The key is optional, with a default value of NO.
Set the value for this key to YES to apply the configuration for the given domain to all subdomains of the domain that have one additional path component. For example, if you set this value to YES and the domain name string is example.com, then the configuration applies to example.com, as well as math.example.com and history.example.com. However, it doesn’t apply to the subdomains advanced.math.example.com or ancient.history.example.com because those subdomains have two additional path components. If the value is NO the configuration applies only to example.com.
If you create an NSExceptionDomains dictionary for an IP address or a range of addresses, the NSIncludesSubdomains key has no effect for that exception.