Reference letters to obtain license by endorsement

I posted in a different section of the allnurses forum with no luck so I thought I'd post here.

MY SITUATION THEN:

A few years ago, literally months after I became an RN, some silly stuff happened with an employer that I briefly worked for and I was reported to the BON, and, over 2 years later (yep, it takes that long) my 'discipline' was issued in the form of public reprimand (fair or not, right or not, that was literally the best thing that could happen and the least amount of 'discipline' possible). I was ordered to complete a couple of NSCBN courses online, and the public reprimand was removed from my license, but it still shows that I was previously 'disciplined'. I'll keep things private for confidentiality, but, FTW, just so you all understand how low it was on the severity scale, it had NOTHING to do with narcotics, substance abuse, etc, or anything r/t criminal charges, counseling or rehabilitation or anything of that severe nature. Was literally pretty minor and related to miscommunication between employee/employer. I was able to keep my current job with no problem and no repercussions when the reprimand was issued.

SITUATION NOW:

Anyway, I'm in the process of applying for a new license and one of the requirements regarding my situation is to provide 3 letters of recommendation. In my nursing career so far, I've never had to do so and got all my jobs without reference letters, so I really have no clue how to go about it.

Does it have to just be supervisors? Can it be coworkers? Personal references? A mix of both? I don't know that I have three solid supervisors this early in my nursing career. Do they send ME their completed reference letters? Do they send them directly to the BOARD? Can they email or does it have to be paper? Do I HAVE to explain to them why I need one or can I be more vague, assuming it's just needed for a new career opportunity or something? If I have to explain, it's fine, I don't feel guilty, it's a mishap early in my career, but obviously I don't want to disclose any more info that I have to.

Thanks guys for any replies!!