My personal rule is adult deer only. Spikes and doe fawns lack quantity of meat and really are not that difficult to take because of their lack of weariness. Locally they have been on a deer reduction push which allowed us to shoot as many as 5 antlerless deer per year. I think it has worked and possibly to well. I will be limiting myself to one adult doe and hopefully one large buck next year. All button bucks can grow into big old boys given enough time and yes you can identify them with a little observation.