They are waxy potatoes, and cook up quite firm-fleshed.
Ditta Potatoes were developed in the Netherlands.
Vergroesen, Jacques. Agrico / Bioselect Potatoes. Report of an excursion to demonstration fields with varieties for organic cultivation on 23 June 2008 at the Kollumerwaard experimental farm in Munnekezijl (Northern Netherlands). June 2008. Retrieved August 2009 from http://www.organicseeds.nl/talen/en/activities.html.