If you be under 1599 when you want to register see that say :
You are registering "out of competition", reason: rating should be between 0 and 1,599 in order to register for the contest.

Please see it is wrong becuse the rating order is between 0 and 1599 but in codeforces we have a people under 0 and that mean they can not rate in div3 contest.
Look like : [problem:kiko_] and fxt