Arthur

1. In version 54, at Churchyard or Town Square, STAND ON GATE says, "The gate is too high to stand."
2. In all versions, if you are human in the nest then you can THROW anything visible: yourself, parts of your body, the sky, etc. You get, "You throw [whatever] to the grove below." If the raven is there and you THROW RAVEN, then it comes right back. THROW GROVE causes serious problems. If you then LAND IN GROVE, the program locks up. If you travel to Grove, almost any interaction there crashes the interpreter. Frotz exits with the message, "Fatal error: Store out of dynamic memory".
3. In all versions, in Cottage, if the peasant is awake, then PUT something ON PALLET is treated as GIVE CRUTCH TO PEASANT, giving it to him no matter where it is. This works even if you have destroyed the crutch in the fire.
4. In all versions, you can't PUT anything ON HORSE; the game criticizes your fashion sense. However, anything you DROP while mounted stays on the horse. While you are mounted, everything on the horse is listed twice in the room description, before and after anything that's on the ground.
5. In all versions, if you EMPTY PALLET after having put something there, you are told the object lands on the ground nearby, but then the program locks up. The same thing happens if you EMPTY BOAR after having thrown something across the chasm to the wild boar, or if you EMPTY HORSE while mounted after having dropped something on the horse, or EMPTY TABLE in Armory. You can also do it with EMPTY TABLE in Tavern Kitchen, but only after the bird gets you the key.
6. In all versions, you can carry any object while you're a badger. If you go to the idiot while the sprig of hawthorn is attached to your fur, then GIVE SPRIG TO IDIOT causes him to give you whatever he has.
7. In all versions, you can pick up objects using WEAR, but you don't score points this way.
8. The cook must carry a spare key to his cupboard. In all versions, if the key and/or spice bottle are in the room but not in your possession when the cook returns to Tavern Kitchen, or if you GIVE or SHOW one of them to him, then he puts them in the cupboard and leaves it unlocked. This works even if you lock the cupboard, throw the key in the chasm, and give the bottle back to the cook.
9. In all versions, there's no consistency to what you can and can't do across the chasm. Anything you throw across the chasm you can't GET, but you can EAT, DRINK, TOUCH, EMPTY, PUT things IN, etc. Also, ATTACK BOAR WITH SWORD has the same effect on either side of the chasm.
10. In all versions, you can ZAP MINNOW over and over before it floats to the surface. Each time you're told you kill it.
11. In all versions, when you're human, EMPTY a body part says, "There is nothing in." When you're a turtle, salamander, or eel, EMPTY HAND says, "You can't empty your . You are [whatever].", and GIVE HAND TO someone says, "You don't have your ."