@Jared Shoemaker Thank you just purchased the audio book on Audible!

I think it will most likely be self-policing.I rented tiny studios in a 26 unit building and most of my tenants were grad students, once we found our niche.  

That said, I don't think 18 people are allowed to pack into a studio apartment.

I have a studio attached to my home that I rent to a young couple.

Food, shops, yoga studios and lots of people hanging around?

Thanks @Luka Milicevic, Account Closed LOVED your (audio) book; I took pages of notes!  

It will have separate metering (electrical, gas, water, etc.) with a private fence to make it "feel" like a private studio. 

Learned this the hard way.You're always better off just saying it's as-is and looking for a tenant who is fine with it as-is.The other option, is if you are having trouble renting a unit, take it off the market, make whatever upgrades you need to in order to get it rented, then advertise it as-is again.Just one story - I had an applicant who looked at a nice big studio I had in the old converted building I managed.  

For marketing, the closest would be comparing to 1 bd/1ba or studios.

What I did was let my tenants sub-let their studio apartments for the summer, so I didn't lose them.