Dumbledore's Army parchment

"I – I think everybody should write their name down, just so we know who was here. But I also think that we all ought to agree not to shout about what we're doing. So if you sign, you're agreeing not to tell Umbridge or anybody else what we're up to."

- Hermione Granger presenting the parchment to the newly-established Dumbledore's Army

A parchment was signed by most members of Dumbledore's Army when the organisation was founded in October of 1995. It served largely as a security measure designed by Hermione Granger, who placed a jinx on it that would detect and identify anyone who betrayed the D.A.

Signing
"Fred reached out for the parchment and cheerfully wrote his signature, but Harry noticed at once that several people looked less than happy at the prospect of putting their names on the list… When the last person – Zacharias – had signed, Hermione took the parchment back and slipped it carefully into her bag. There was an odd feeling in the group now. It was as though they had just signed some kind of contract."

- Description of the parchment being signed

In 1995, Dumbledore's Army was founded by Harry Potter, Hermione Granger, and Ron Weasley in order to learn practical Defence Against the Dark Arts, oppose Dolores Umbridge’s dictatorial rule of Hogwarts, and prepare to fight Lord Voldemort and his Death Eaters.

Although student organisations had not been banned by Umbridge when the D.A. was initially formed, it was expected that she would oppose the group’s existence, thus secrecy was paramount. Hermione informed the group that gathered in Hog's Head of this, and presented them with a parchment to sign. She told them that it meant they had to keep the group secret, but did not inform them that she had placed a jinx on the parchment that would cause anyone who signed the parchment and betrayed the D.A. to break out in boils that spelled “SNEAK” across his or her face.

Fred Weasley signed first and without hesitation, followed by George, but the others were more reluctant. Ernie Macmillan was the only one to voice his objection, arguing that the list would be incriminating if it were found and worried for his Prefect position. Harry reminded Ernie that he had previously argued that the D.A. was the most important thing they could do that year, and Hermione assured him that she would protect the parchment. Ernie finally signed, and everybody else followed; Zacharias Smith was the last.

Breach
Later in the school year, Marietta Edgecombe betrayed the D.A. to Umbridge, triggering the jinx on the parchment. The Inquisitorial Squad raided the Room of Requirement, and Pansy Parkinson found the parchment. Most D.A. members managed to escape punishment, since Albus Dumbledore took the blame and secret Order of the Phoenix member Kingsley Shacklebolt used a Memory Charm on Marietta.

Signatories

 * Hannah Abbott
 * Katie Bell
 * Susan Bones
 * Terry Boot
 * Lavender Brown
 * Cho Chang
 * Michael Corner
 * Colin Creevey
 * Dennis Creevey
 * Marietta Edgecombe
 * Justin Finch-Fletchley
 * Anthony Goldstein
 * Hermione Granger
 * Angelina Johnson
 * Lee Jordan
 * Neville Longbottom
 * Luna Lovegood
 * Ernie Macmillan
 * Padma Patil
 * Parvati Patil
 * Harry Potter
 * Zacharias Smith
 * Alicia Spinnet
 * Dean Thomas
 * Fred Weasley
 * George Weasley
 * Ginny Weasley
 * Ron Weasley

Behind the scenes

 * Seamus Finnigan did not sign the parchment, but became a member of Dumbledore's Army eventually.

Appearances

 * Harry Potter and the Order of the Phoenix