“I don't mean to be rude—" he began, in a tone that threatened rudeness in every syllable."Yet, sadly, accidental rudeness occurs alarmingly often," Dumbledore finished the sentence gravely.”

“He accused me of being Dumbledore's man through and through.""How very rude of him.""I told him I was."Dumbledore opened his mouth to speak and then closed it again. Fawkes the phoenix let out a low, soft, musical cry. To Harry's intense embarrassment, he suddenly realized that Dumbledore's bright blue eyes looked rather watery, and stared hastily at his own knee. When Dumbledore spoke, however, his voice was quite steady. "I am very touched, Harry.”

“Professor, why couldn't we just Apparate directly into your old colleague's house?''Because it would be quite as rude as kicking down the front door,' said Dumbledore. 'Courtesy dictates that we offer fellow wizards the opportunity of denying us entry.”

“The Prophet is bound to report the truth occasionally,' said Dumbledore, 'if only accidentally.”

“Harry picked it up and stared at it, his heart twanging like a giant elastic band. No one, ever, in his whole life, had written to him. Who would? He had no friends, no other relatives — he didn’t belong to the library, so he’d never even got rude notes asking for books back. Yet here it was, a letter, addressed so plainly there could be no mistake:Mr. H. PotterThe Cupboard under the Stairs4 Privet DriveLittle WhingingSurrey”

“Let me out," Harry said again."No," Dumbledore repeated."If you don't - if you keep me in here - if you don't let me-""By all means continue destroying my possessions," said Dumbledore. "I daresay I have too many.”

“Anyway, members of the Inquisitorial Squad do have the power to dock points so, Granger, I'll have five from you for being rude about our new Headmistress. Macmillan, five for contradicting me. Five because I don't like you, Potter. Weasley, your shirt's untucked, so I'll have another five for that. Oh yeah, I forgot, you're a Mudblood, Granger, so ten off for that.”