Masking Spell

Masking Spells are a wide range of charms that can be used to mask the presence of a witch or wizard, thereby making them untraceable. Thus owls cannot be used to track or send post to them, one of the few reliable methods of doing so, along with Disguising Spells and Repelling Spells.

Appearances

 * J. K. Rowling's Official Site
 * Pottermore