Quoting https://lieber.westpoint.edu/release-prisoners-war/ :
> First, able-bodied POWs may be partially or wholly released on parole or promise if national law of the detaining power that of the State of origin of the POW permits this (art. 21, GCIII). As explained by the 2020 ICRC Commentary to GCIII, Article 21: “Such release typically occurs in exchange for a pledge not to take up arms again in the same conflict. The practice of paroling prisoners of war has declined considerably since 1949. In addition, many States today prohibit members of their armed forces from accepting release on parole” (para. 1920). Prisoners of war released on parole are compelled to keep their parole or promise.
I can't tell if this means parole for those interned in a foreign country, or if they were allowed to return home under parole so long as they didn't fight.
In looking around, I also found https://ses.library.usyd.edu.au/bitstream/handle/2123/7995/W... about the parole system in the US Civil War. It comments:
> The American Civil War was the last western conflict where paroles were regularly employed and honoured by both armies. 14
where 14 is:
> There were instances of parole in the Franco-Prussian War (1870-1871), the Boer War (1899-1902) and the First World War, but in general terms, after the American Civil War, the practice began its demise. For the Franco-Prussian War, see: Michael Howard, The Franco-Prussian War: the German Invasion of France, 1870-1871 (New York: Routledge, 2004), p. 222. The Prussian army allowed French officers to leave on their parole after the Prussian victory at the Battle of Sedan. For the Boer War, see: Major Gary D. Brown, ‘Prisoner of War Parole: Ancient Concept, Modern Utility’, Military Law Review, vol. 156 (June 1998), p. 207. The Boer guerrillas tried to place British POWs on parole, but these were largely disregarded. For the First World War, see: Paul Robinson, Military Honour and the Conduct of War: From Ancient Greece to Iraq (London and New York, 2006), p. 156. The French placed some German officers on parole early in the conflict, but the practice was not reciprocated by the Germans
A comment at https://history.stackexchange.com/a/66023 says:
> In summer 1940, the German Wehrmacht had captured 2 million Dutch, Belgian and French soldiers. All of the Dutch and Flemish and about a third of the French POWs were released on parole because the Germans coulnd't supply them and already had half a million Polish POWs as workforce (de facto: slaves). Mark Mazower, Hitlers Imperium: Europa unter der Herrschaft des Nationalsozialismus. C.H.Beck, Munich 2009. Page 152
You'll likely have to ask in a more specialized forum to find the information and documentation you're wondering about.