Is NM cable a raceway? I remember not being allowed to run NM cable in pipe because you can't combine 2 raceways together. Having said that can you run se cable from a main panel and feed a sub panel under the 10ft tap rule?
NM Cable is a type of wire meaning non metallic. It is not a raceway just a type of covering and yes you can not run Nm with any other sheathed cable.You can run a SE Cable to a sub panel as long as it is a 4 conductor wire that will serve the amperage of the sub,You still need to install a breaker for the sub panel.