: universalk9 . This is a universal image containing all software features; specific features (like IP Base or IP Services) are enabled via software licenses.
Engineers often used this image to upgrade switches from older versions. An upgrade from 12.2(55)SE to 15.0(2)SE11 wasn't just a simple file copy; it was a significant event. The switch would automatically upgrade its c3750e-universalk9-mz.150-2.se11.bin