ulType (ULONG) - input
If the category is PRTALERT_CATEGORY_CORE, then this is a bit-field that defines the core alerts to unregister.
If the category is not PRTALERT_CATEGORY_ALL, PRTALERT_CATEGORY_CORE, PRTALERT_CATEGORY_ALL_CORE, or PRTALERT_CATEGORY_ALL_EXT, this is a value that defines the specific extended alert to unregister.