What this translates to is: Give me matches that include the keyword Aliyev, but also me matches that include up to any 2 letter variations from the keyword Aliyev. These variations include adding, removing, and changing a letter. This includes Aliyev, of course, but also includes Əliyev, which is just one letter variation different, and Əliyeva, which is two letter variations different from Aliyev.