1) The host school is the one who appoints/designates the DMP.
2) The referee should ask the host school if they have a DMP onsite. The people the referee should ask that question would include the Athletic Director, the Tournament Director or the Head Coach.
3) If the host school tells the referee there is a DMP, they should also point out that person to the referee or introduce them to the DMP. Stated another way, the referee needs to know specifically who that person, the DMP, is. That way, if the DMP needs to be consulted, the referee knows which person needs to be brought into the situation.
4) The referee will not take any steps to investigate the qualifications of the DMP. The host school is responsible for that, and the referee will simply take the school at their word. That is why the referee is taking the answer to the question, "Who is the DMP?" from only the selected people I listed in # 2, and not from a wrestler, a random spectator, a table worker, etc. The referee will not be asking the DMP to produce a diploma from a certified medical school, a state issued license to practice medicine, a list of professional references, etc. - the school would be the party to determine that a particular person is qualified to be the DMP.
5) The medical opinions and judgments of other people present at the event are subordinate to the DMP. Stated more provocatively, people other than the DMP have no standing when it comes to rendering the official medical judgment for a situation happening in the wrestling event. For example, if the DMP says a wrestler is contagious and should not be allowed to wrestle, that trumps 100 random doctors and nurses who happen to be attending the tournament and have an opposing opinion. The referee will leave it to the DMP to decide if, and how, they might incorporate the opinions and judgments of professional colleagues who happen to be present at the site, but are not filling a role as a "designated" medical person. The referee will not consult the 100 random doctors and nurses - the referee will only consult the DMP for the opinion/judgment regarding a medical question (e.g., assessment of contagious condition, concussion management assessment, etc.).