From: Groenfontein
This Prisoner of War record for Nicholas Johannes Van Schalkwyk was transcribed record from various documents held at the National Archives, South Africa, including arrest and shipping information from newspaper sources like De Zuid-Afrikaan.
https://www.gendatabase.com/boer-war-prisoner-record.php?q=13438&r=Nicholas Johannes&s=Van Schalkwyk&ref=
This set of Prisoner of War documents can be accessed online via the FamilySearch.org project by Clicking Here.