Shibboleth, a term originating from the Bible, entered the English language in 1638 and is utilised as a form of "linguistic password" to discern whether a person's spoken language is their native tongue.
In the midst of the Russian invasion of Ukraine in 2022, Ukrainian troops employed the word "palianytsia" (the Ukrainian term for a loaf of bread) to distinguish Russian reconnaissance troops or spies. The word "palianytsia" then functioned as a shibboleth, as it proved challenging for many Russians to pronounce correctly.
The Dutch historical equivalent is the word "Scheveningen" — it was employed following the German invasion of May 1940 to differentiate between Dutch nationals and German soldiers or spies.  A ‘linguistic test’. While most Dutch individuals can effortlessly pronounce this word, many foreigners struggle with the Dutch pronunciation due to the complex "sch" sound.