I'm abandoning my Missing.no, as I have two, and I hope someone will look after it <3 I'll reply to everything else later, so don't worry, I haven't missed you deliberately, I'm just in a rush now.When there is a Pokémon Exchange active, you may enter a enter one of your eggs or Pokémon in the Exchange. Upon doing so, you will immediately be credited a number of points based on the rarity of your deposit, and also if it is breedable or not. Once you enter a Pokémon in the Exchange, you will be unable to obtain it ever again (just as if you had abandoned it), and you will also be unable to take back your deposit. Until the Exchange is complete, you will also have your maximum party space reduced by one (thus, you will only be able to carry five Pokémon around with you, as opposed to six). Pokémon, regardless of their level, when deposited, will also revert to completely unhatched eggs.
At the time of the exchange, the eggs will be randomly sent out to the users who entered in the Exchange. You will only receive something of the same rarity of your desposit, so you don't have to worry about deposting a Legendary and only getting a Common Pokémon in return.