The rook piercing is an ear piercing located above the tragus . It is not feasible for everyone because it is located on the small fold of the ear which is not found in everyone.
Since it is located directly above the daith, piercers (and pierced too!) often confuse these two piercings, which are quite different.
When doing a rook piercing , make 100% sure that you are asking for the piercing you want. It's a good idea to bring photos so you and your piercer are on the same page.
As a cartilage piercing, the overall aftercare doesn't differ too much from any other cartilage piercing. However, its location in the folds of the cartilage makes it a difficult piercing for you during follow-up and for your piercer during the piercing.
