This property is useful to determine whether the property DACL should be considered if its value is nil. A nil DACL is considered as "allow everybody". If DACLPresent is true and DACL is nil and any of the Create_SD and Create_SA function is called, the newly created winapi security descriptor will have a NULL DACL and so allow everybody access; otherwise the SD will not have a DACL at all. 

This situation is equal to a DACL with an access entry that grants GENERIC_ALL to World SID. 

This property is automatically set to true if a DACL was set to a value different to nil; otherwise it won't be set. 

The initial value is true.

TJwSecurityDescriptor Properties