Technically what he means by "rare" is that you would have to begin playing rs from a long time ago to snag up a normal "name" such as Xmas or Kitty, since nobody played too much around that time. But now there's so many people playing rs that we all have to go by names such as "Lkger" or "AK47newb" or "mysokewl" or random number names like "899 Eagle" and "freeze 77639"
Rare and unique are completely different things. Words/Names are rare. Random letters such as mine/ or four letter names are not rare in the slightest.