There is no such thing imao. Either presales are made among strategical investors or people close to owners, either they are listed here on the forum. If the ICO company desire then they only allow general public to enter ICO on the stage of general "sale" only.
So you have all rightly said, but there are also projects that allow you to go into the pre-sale and ordinary people, but if I honestly think such projects are pessimistic if they are already collecting money without anything