[Codex]

Spoiler for eye-catch in episode 13:

The second rule states that "The DEATH NOTE will be rendered useless if the victim's name is misspelled four times."

Didn't Light do that already in the very beginning, when he was trying to kill the guy harrassing a woman outside the convenience store by listing all possible spellings of his name? Does the rule have a different meaning, did the author forget about this, or ... ? (Avoid manga spoilers please)

EDIT: Thinking about it now ... I guess the rule means that the Death Note will not work on a particular victim if that person's name is misspelled four times, and not the power of the notebook as a whole. And I suppose it is possible that Light got the man's name right within the first four tries, and the Death Note took effect even though he kept writing the wrong kanji after that.