Rosetta Stone
The Rosetta Stone was an ancient  artifact inscribed with Egyptian hieroglyphs alongside the same text in Greek and another Egyptian language, which helped Human archaeologists on Earth translate what was previously indecipherable. It was a common metaphor for key discoveries in translation.

In his personal log, Captain Donald Varley described an Iconian device as "a galactic Rosetta Stone." ()

In 3190, Captain Michael Burnham compared the discovery of Species 10-C's pheromone-like hydrocarbons in a Species 10-C nursery to the Rosetta Stone, as they represented a possible key to being able to communicate with them. Doctor Hirai later additionally noted that the Rosetta Stone required understanding of two languages to understand the third. ()

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de:Stein von Rosetta
fr:Pierre de Rosette
Linguistics
Earth literature