While filling out a job application, I noticed a small label designating M/F/D/V.
Is this important? What does this label mean?
Ever hear an advertisement that "Company X is an Equal Opportunity Employer?" Technically, it doesn't really mean anything - it's against the law to use information on any of the protected groups as a deciding factor for hiring - the protected groups being: race, skin color, ethnicity, religion, gender, orientation, and physical disability. (Correction, it looks like the page is a bit out of date, and Veteran was added to the Protected Groups back in 2015.)
It's the same thing as M/F/D/V - it's just something that doesn't technically mean anything, apart from "We follow the law, and don't discriminate." Because discriminating based on Male/Minority, Female, Veteran, or Disabled is already against the law.
Beyond that, the intent upon adding it could be any number of things. It could be simple boilerplate upon a standard job listing. It could be an active attempt at virtue signalling. It could be a company trying to get past a black-eye over discriminatory practices in their recent past. It could even be trying to subtly get more people with a non-majority status in one of those groups to apply (aka, more women, minorities, veterans, or disabled people.) Honestly, though, the best guess is probably just Boilerplate.
I don't see that notation on postings as much as I used to. My understanding is it is an attempt to notify people they follow all US Government guidelines about non-discrimination against those categories of people. I've seen the M as either minority or male. F = female, D=disabled, V=veteran. Also, I think, government projects get extra points for having people from those categories employed. Its certainly not saying ONLY people from those categories will be hired, that would be discrimination just as much as saying they would not be hired for the position.