I read that the Society for Human Resource Management (SHRM) recommends the use of a signed disclosure form for volunteer workers. The article is called "Employing Interns" and is described as follows:
The article discusses pragmatic reasons for employing interns, practical considerations with employing interns and compliance with U.S. law concerning internships.
The Conclusions section of the article states:
Employers with unpaid internship programs should develop standard disclosure forms to be signed by prospective interns acknowledging, among other things, that no job is being offered in connection with the successful or unsuccessful completion of the internship. The internship should have specific start and stop dates. In addition, the employer should obtain the intern's signature on a document stating the intern understands that he or she is participating in a valid internship and therefore will not be entitled to wages (or only to minimum wages) for the time spent in the internship. On this matter, the employer should probably consult with legal counsel, and legal counsel will probably want the document to include much more detail. The greater the number of interns involved, the greater the risk if the details are overlooked.
Misclassification of interns as trainees rather than employees could result in the interns being deemed employees eligible for Social Security withholding and matching, unemployment insurance benefits and workers' compensation. The tax ramifications for an organization having "employees" for whom FICA taxes have not been withheld and paid can be substantial, including a 100 percent penalty for FICA withholding not actually paid by the employer.
For large-scale and ongoing internship programs in which the employer wants to pay less than the applicable minimum wage or overtime, legal counsel should be consulted.
I would like to know whether Stack Exchange has developed, and whether it's in the habit of getting signatures on, a "standard disclosure form" for its new moderators. If so, what does it say, and approximately when was it instituted?
Is "unpaid internship" a reasonable approximate description of the role of a volunteer moderator?
My research: a Bloomberglaw article states:
[Under current law] a position can be properly classified as an unpaid internship if the intern is truly the primary beneficiary of the working relationship.
Update:
I've done some more research into the employment status of volunteer moderators at SE. Rather than completely rewriting this question, I'd like to get rid of it and start fresh. But apparently I'm not supposed to delete it, because it has a good answer. So I am voting to close. Weird, I know, but that's the best solution I could think of.