These would generally include more detailed breakdowns of data or tables to support statistical releases which cannot be produced according to the primary production timetable.
Byddai’r rhain yn gyffredinol yn cynnwys dadansoddiadau manylach o ddata neu dablau i gefnogi datganiadau ystadegol na ellir eu cynhyrchu yn unol â’r brif amserlen gynhyrchu.