Player's Handbook[]
The character has mastered a difficult and obscure tongue, now primarily found in the writings of pedantic sages and sorcerers. The main use of the language is to read tomes of ancient secrets written by long-dead mystics. This proficiency enables the character to either read and write or speak the language (his choice).
Player's Option: Skills & Powers[]
Ancient Languages: Adventurers with this proficiency are familiar with at least one ancient language—i.e. they have the reading/writing proficiency with the chosen languages. If confronted with an example of a historically-related language, they can decipher about a paragraph of that tongue with a successful proficiency check. For each character point spent on this proficiency (after initially acquiring it) add one additional ancient language to the list of languages a character knows fluently. The precise memory trait provides a +2 to this proficiency rating.
The Complete Barbarian's Handbook[]
The barbarian has mastered an obscure language associated with his homeland. Ancient barbaric languages don't necessarily involve words; they may consist of grunts, snorts, tongue clicks, or whistles. This proficiency enables the barbarian to vocally reproduce the language; he can't write or read it. The player should provide an explanation for the barbarian's fluency.
Campaign Option: Council of Wyrms Setting[]
This proficiency is described in the Player's Handbook: It allows a dragon to either speak or read and write a specific ancient language. Hatchlings can't select this proficiency.