Quoted from PinCrush:
Alice Coopers Nightmare Castle = ACNC - not NC
Rob Zombie's Spookshow International = RZ - not SI
Elvira's House of Horrors = EHOH - not HOH
John Carpenter's Halloween = JCH - its right there on the backglass and topper
HWN is not even an acronym. Its an abbreviation that isn't necessary because a TLA is right there printed on the game.
In this context, it makes sense. Still prefer HWN lol. Doesn't need to be an acronym as the point of all of it is just shortening the names.