Definition of the root NeXus group. The root of any NeXus data file is an NXroot class (no other choice is allowed for a valid NeXus data file). This attribute cements that definition. Date and time file was originally created File name of original NeXus file Date and time of last file change at close Version of NeXus API used in writing the file Version of NeXus API used in writing the file Version of NeXus API used in writing the file. Note this attribute is spelled with uppercase "V", different than other version attributes. Version of NeXus API used in writing the file facility or program where file originated entries