U+12157 Cuneiform Sign Ka

The Wikipedia has the following information about this codepoint:

The cuneiform ka sign is a common, multi-use sign, a syllabic for ka, and an alphabetic sign used for k, or a; it is common in both the Epic of Gilgamesh over hundreds of years, and the 1350 BC Amarna letters. Cuneiform "ka" is nearly identical to a similar 'mid-size' to larger cuneiform sign, ša (cuneiform); because both ka, and ša have two separate specific uses, once these usage sites are identified on a specific Amarna letter, for example, the difference between the two can be followed.

Cuneiform ka has a secondary use as the pronoun suffix, -yours. For Ayyab's letter, EA 364 (pictured), after addressing the Pharaoh, part of the Introduction, is to state "...Servant-yours, ...." Specifically, Ayyab is from one of the vassal states/city-states/towns in Canaan, thus the relationship to the Pharaoh in the Amarna letters often state a relationship of being the Pharaoh's servant. This is dramatically juxtaposed against the Amarna letters from Tushratta of Mitanni, (letters EA 19, EA 23, EA 26, EA 28, EA 30-(only a passport-type, short letter), etc.), or from Babylon, or the King of Alashiya. The letters from those kings have long lists, as part of the Introduction stating: May you (King, pharaoh) have peace (health), ... for, wives-yours, for sons-yours, for magnates-yours-("sa-meš"), etc.

For cuneiform ša, its specific sub-usage (besides as a syllabic, or alphabetic), is as a segue form of a conjunction typically at the beginning of a statement, translated as: "which...", "what...", etc., with the rest of text to follow.