Unknown writing

The  is one of the two known writings existent in the universe of the Attack on Titan manga, along with the Walls Writing. It is a mysterious writing that so far only Ymir has been confirmed to be able to read.

Description
The Unknown Writing is very similar to the Walls Writing, although it is known to be a different language since none of the Survey Corps members (seemingly including Reiner, a warrior from the Hometown) present at Utgard Castle were able to understand it; with the only exception of Ymir. The reason why she can read the writing and whether this is a common trait for the Subjects of Ymir or it is an ability exclusive to Ymir is still unknown.

Appearances
The existence of the Unknown Writing is revealed when a small group of Survey Corps members (including graduates of the 104th Training 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.

Trivia

 * Page_of_Ilse's_notebook.png the Walls Writing, the Unknown Writing is simple Japanese katakana turned upside down and messily written to make its reading difficult and give the impression that it is a different language. However, unlike the Walls Writing which is read left to right (like regular Japanese), the Unknown Writing is read right to left.
 * Eren_in_Titan_form_remembers_his_father's_fate.pnger possible case of the Unknown Writing is found in Ilse Langnar's notebook. As she is running trying to reach Wall Rose after the failed 34th expedition beyond the Walls, she writes on her notebook a journal of her experiences, and the text is katakana turned upside down and right to left, like the writing on the can of herring.However, it has not been confirmed that this is indeed intended to be the same language.
 * When Hange Zoë is doing experiments to Eren Yeager in Titan form, Eren begins to write in the ground. The messages say that he cannot figure out how to harden his Titan form, followed by "my father" and "did to me". In one of the panels, Eren is depicted writing "ate" (クッタ) in a style similar to the Unknown Writing, referring to how he was forced to eat his father.