|Muggles' Guide to Harry Potter - Magic|
|Features||Marks a surface|
|First Appearance||Harry Potter and the Order of the Phoenix|
Flagrate is used to mark things, such as doors, with a flaming mark of some sort.
As they enter the Department of Mysteries at the Ministry of Magic, Harry and his companions find themselves in an antechamber with a number of identical doors, that seem to spin around every time a door is closed. As a result, it is impossible to tell which doors have already been tried. Hermione uses this spell to mark each door they try, until they find the correct one.
Despite the similarity in names, this spell seems to be not particularly similar to the Flagrante curse.
We note that Hagrid created a fire in the fireplace when visiting the Dursleys at the Hut on the Rock. While it's possible he used this charm, we note that the book describes the result as "a roaring fire", rather than a flaming mark. The result of the spell suggests strongly that some other charm was used at that point.