Cancellation

Cancellation is the term for removing magic from an object or disabling the special attack of a monster. The most common source of cancellation is the wand of cancellation. A few are able to use the spellbook of cancellation. Those wielding Magicbane can sometimes cancel monsters that way.

Cancellation of objects
Cancellation typically removes all charges from an object, removes enchantment (resetting weapons and armor to +0), and changes magical objects into nonmagical ones (for example, making bags of holding into simple sacks and removing magical labels from scrolls). It even removes blessings and curses from objects! In short, cancellation is quite thorough.

Canceled wands cannot be recharged. (This fixes a bug that had allowed players to gain infinite wishes by cancelling their wand of wishing.)

Considering when to cancel
Suppose you need some blank scrolls and spellbooks and some potions of water, because you plan to use your magic marker and make holy water. You have two choices; you could wet them or you could use cancellation.

If you can find a wand of cancellation, then a strategy is to initially use cancellation. This is because you can pile all your junk scrolls, spellbooks, and potions, then zap it with only one charge. However, once you acquire water walking, do start dipping things into a moat. (Remember to kill the ;| first!)

The advantage of this strategy is that you do not need to use fountains, whether you already dried every fountain or you just want to avoid the nasty side effects. When you switch to the moat, you can save cancellation for use against monsters, and you can also dilute your potions of fruit juice.