If I read the threadstarter's post correctly, he/she is saying "Why doesn't the organiser (or Admin) state that the nude shoot is for targetted (meaning >18/21 yrs old) audience only?"
Well, here are our thoughts :-
a) Organiser already states in the title or within the thread thats its Nude shoot (whether photographer in the nude, model in the nude, or both in the nude is outside the discussion here) thus it implicitly already targets a specific audience - eg the nude shooters.
b) We do allow display of artistically inclined shots, thus going into a thread that shouts out NUDE! does not necessarily mean that you get an eyeful (of a nude model or a nude photographer) - but members are advised to insert the URL link of the image(s) and not embed it as an image, so that member discretion can be used to physically click on the image link to view.
c) When members sign up for a shoot (in the nude or otherwise), organisers have no way of knowing whether the member is underaged or not, thus it will only when the members turns up at the shoot date/time (again in the nude or otherwise), the organiser will then have to decide whether to allow the member to partake in the shoot.
We believe that there are enough checks and balances in the system to not have to micromanage the nude shoots.
Thanks for your understanding.