MOS question

[bubblyOoorah]

When looking up possible jobs I noticed that some of them list "Must be a volunteer" under the criteria. What exactly does this mean? Does that mean your recruiter cannot give you the job without you asking for it? or does it mean that you can volunteer to do that job on top of the job you already have? The job in particular I was looking at was 0472.
Thanks in advance.

[Agent Johnson]

It means you can't be forced to take that job, if you enlisted under another 04xx job they can't make you a 72 unless you ask or tell them it's ok to be one.