When this line is executed inside a sub-program file, control returns to the main program.
MASSO supports sub-program calls using M98 and M99.
Up to 5 levels of sub-program nesting are supported.
Sub-programs allow commonly used toolpaths to be reused without rewriting the same code multiple times.
When a sub-program is called, MASSO looks for a separate .nc file and runs it as a sub-program.
Using separate files allows common program sections to be shared between different jobs.

M98
P value – Defines the sub-program file name
L value – Optional. Specifies how many times the sub-program will run
N10 M98 P10 L5
MASSO looks for the file 10.nc as defined by the P value.
The file is executed 5 times as defined by the L value.
The M99 command ends a sub-program and returns control to the main program.
M99
N10 M99