It's a boffinism! Some fields/sectors do use it like a mass noun as you point out. Often refers to a set of routines or a library. So something like "ocean m

It's a boffinism! Some fields/sectors do use it like a mass noun as you point out. Often refers to a set of routines or a library. So something like "ocean model codes" means packages of routines or libraries for ocean weather simulation.