Eldian language (Anime)

The unknown writing is one of the two known writings existent in the Attack on Titan universe, along with the Walls writing. It is a mysterious writing that so far only Ymir has been confirmed to be able to read, although Reiner likely could decipher it as well as shown when he recognized the writing.

Description
The unknown writing is very similar to the Walls writing, although it is known to be a different language since none of the Scout Regiment members (possibly including Reiner, a Warrior from beyond the Walls) present at Utgard Castle were able to understand it; with the only exception of Ymir. The reason why she can read the writing is still unknown.

Appearances
The existence of the unknown writing is revealed when a small group of Scout Regiment members (including graduates of the 104th Cadet Corps) take shelter at Utgard Castle and find several mysterious crates left recently by unknown occupants. They discover that the crates are full of supplies labeled in a strange language they can not understand. However, Ymir inadvertently reveals to Reiner that she is able to read the writing when she reads the label of a can of herring.