The badges presented in the movie were worn by the people brought from Poland in the capacity of the forced labourers in the agriculture and industry in an attempt to make up for the decreased manpower caused by mass conscription and, in the later stages of war, also by the losses among civilians (it is estimated that throughout the war, roughly 2.8 million Poles were brought to Germany as forced labourers).

The badges were introduced by the Heinrich Himmler's 'Polish Decrees' (ger. 'Polonerlasse') of 8th March 1940 (Reichsgesetzblatt 1940 I, Nr. 55) that mandated all Poles brought as forced labourers to carry such badge (a yellow rhombus with a violet edge and letter 'P', the colours are visibly distorted by the colouring process in a movie) on a right side of an outermost item of clothing, so that it was always visible. It is worth noting that this particular badge was the first of three badges people in Nazi Germany were forced to wear. Introduced in 1940, it has been later followed by the yellow six-pointed star worn by Jews since 1941 and a blue rhombus with the white letters 'Ost' (German for 'East') worn by forced labourers from Soviet Union, introduced in 1942.

Nominally, lack of such badge was punished by a fine up to 150 Reichsmarks (although eyewitnesses usually state that actual fines were far lower, often in the ballpark of 10-20 RM) or up to 6 weeks of arrest, although police rarely bothered to check them, and given lack of obvious differences between Poles and Germans, the ethnicity could have been exposed only during control of documents or having one's conversation in Polish overheard. Arrests were rare, because police understood that such measure is counterproductive and will only cause trouble if the employers of the arrested come with complaints. This caused many Polish labourers, especially those speaking fluent German and working in the villages, to hide the badges or decline to wear it, as Polish and Soviet labourers were denied many rights, such as ability to use public transport or cultural facilities.

Most of these badges were made in the Berliner Fahnen-Fabrik Geitel und Co. that, as the name suggests, chiefly produced flags and banners. The same company also produced at least a million of the the yellow stars intended for Jews in Germany and occupied territories.

Hodorowicz-Knab, S., Naznaczone literą „P”. Polki jako robotnice przymusowe w III Rzeszy 1939-1945. [Marked with letter 'P'. Polish female forced labourers in the Third Reich 1939-1945]. Wydawnictwo Literackie, Warsaw 2018.