The cuneiform sign for la (𒆷), and also in the Epic of Gilgamesh the sumerogramLA-(capital letter (majuscule), is a common-use sign for the Epic and for the 1350 BC Amarna letters. It is used for syllabic la, and also for alphabetic l, or a.
Epic of Gilgamesh use
In the Epic of Gilgamesh it used in the following numbers: la-(348), LA-(5) times.[1]
Amarna letter usage
The Amarna letter usage of cuneiform la is common for the spelling of Akkadian language "lā", English language, "not", as it is composed of 'la-a'-(). It is also used infrequently for just 'la', for "not", (lā).
References
^Parpola, 1971. The Standard Babylonian Epic of Gilgamesh, Sign List, p. 155, Sign La.