For some categories, not all levels may be available to match. The M1 is an example of this where it may not be available for all job families.
If you find an M1 is missing, please verify on the Year-Over-Year mapping or look at the job code in the job matrix to see where a job has been mapped to for the survey year.
Notice that this Communication-Network Planning Engineering does not have M1 available:
To help you map to a job that may have previously had a M1 level, you should see the M1 job code in the legacy section of the job details.