How do you use the file-cat= command?

[m.e]

How do you use the file-cat= command? If I understand correctly this command could be used to play split files as if they were part of a unique file. But there is no documentation on how it is used. Does anyone know?

[m.e]

I found out myself, if anyone wonders its
vlc "file.part1" --file-cat "file.part2","file.part3","file.part4"