They're called letter jackets, not leather, like Orph said. It's short for letterman, which is a student who excelled in a certain branch at school, traditionally sports, but I received one for academics. The letter is a cloth patch in the shape of the school's first initial. People would sew them to their jackets, but I think that's fallen out of style, or at least it had in my area.
I see that the misunderstanding has been cleared up, but I fought my phone's autocorrect to make this post, so I'm not deleting it.