Bilingual texts are particularly important for the study of antiquity, especially when one language is known and the other is not. In such cases, a text of this nature, provided it is long enough and the translation is precise enough, often provides the key to beginning the decipherment of the unknown language. Once this process has been initiated, the study of the previously unknown language can be expanded to monolingual documents in that language. Subsequent discoveries of more bilingual material can still be significant as they allow for verification of assumptions made or provide a better understanding of variations within a language.
A classic example of a bilingual text that has played a key role is the Rosetta Stone, which is one-third in Greek, a known language. The other two parts are in Egyptian, using two different scripts in which this language was written. This is another aspect of such documents: they can also contain the key to a particular script. Thus, the Rosetta Stone is bilingual but "triscriptal," although this term is rarely used.
