This edition is sometimes referred to as the LXX, because the roman numeral LXX is the number 70. This usage is usually familiar to scholars and serious readers in the context of scriptural texts, but not to a general audience.
The Septuagint translation was used by the Greek-speaking portion of the Christian Church in the first few centuries of the Church The Eastern Orthodox Church still prefers to use the Septuagint for translating the Old Testament into other languages.
See also Sinaiticus codex