I would personally prefer this stay fairly loose and only exclude recruiters/middlemen who have no relationship to the hiring company. These are the people blowing up my phone and inbox based on one random keyword from a resume or profile.

On the other hand, an in-house recruiter, an outside recruiter contracted by the company, the actual hiring manager, just a peer or colleague, the company's receptionist... I think all these should be allowed.

If we're going to cut one more cohort from the above paragraph, cut the 3rd party recruiters. However, excluding all talent acquisition teams and/or other co-workers within the company seems unnecessarily restrictive.