I am creating a generic class that requires me to check the SerializedPropertyType of it's fields, and for the most part I know what each value of SerializedPropertyType means, but there are two values that I do not, and the API Documentation provides no useable information, the two values in question are SerializedPropertyType.ManagedReference, and SerializedPropertyType.FixedBufferSize.
The page for ManagedReference states "Managed reference property." as the description and for FixedBufferSize it states "Fixed buffer size property.", neither of which tell me what those types are used for.