This letter is not ELC letter from UC.

 it just means that the students are in the top 15% GPA at your high school. See below: 

---------------------------------------------------------------------------------------------

Students in the top 15 percent of their rising senior class receive a letter from UC in September, congratulating them on their academic achievement and encouraging them to apply to UC. 

 

-----------------------

ELC is top 9% in their high school based on UC benchmarked GPA.   ELC status is determined when the UC application is submitted. All UC applicants from participating schools will automatically be screened for ELC