(To solve this metapuzzle, you'll need the answers from a certain subset of daily puzzles.)

The skills imparted by the Tome of Understanding will allow you to command any language, be it Semitic, constructed prior to 1915, East Asian, constructed after 1915, or even Slavic! (In that order!)

And it accomplishes all of this with simple two-letter codes.

Answer Checker: Check

Hints: um, remind me to put hints here partway through EnigMarch