rosettamainen
Rosettamainen is a Finnish adjective that translates to something akin to "Rosetta-like" or "Rosetta-stone-like" in English. It is used to describe something that serves as a key to understanding or deciphering a complex or previously obscure subject, text, or phenomenon. The term draws its meaning from the Rosetta Stone, an ancient Egyptian artifact inscribed with a decree in three scripts: hieroglyphic, Demotic, and Ancient Greek. Because scholars could read Ancient Greek, they were able to use it as a basis for deciphering the other two, previously unreadable, scripts.
Therefore, when something is described as rosettamainen, it implies that it provides the crucial information or