You can decipher writing in an unfamiliar language or in an incomplete or archaic form.
Check: you can interpret written messages (as per the Decipher Script skill description in the PHB) and translate written arcane spells ( as per the Spellcraft skill description in the PHB).
Synergy: 5 or more ranks in Translate gives you a +2 bonus to Bluff checks made using the Trick Magic Device feat involving written arcane magic. Conversely, 5 or more ranks in Knowledge (Arcane Lore) gives you a +2 bonus to Translate checks involving written arcane magic. These bonuses increase by +1 for every additional 10 ranks (that is, +3 at 15 ranks, +4 at 25 ranks, and so on).