A typo.
HCI would be a non-existant molecule to my knowledge. A carbon (C) requires 4 bonds to be happy. Iodine (I) can only bond once, same as a hydrogen ion (H).
But, Cl (chlorine) can have one bond to be happy (same is iodine as they are in the same row on the periodic table).
That is your chemistry lesson for today - my lad.
BTW - way to post this thread twice.