XIVAuth claims the use of 1.3.6.1.4.1.65394. as its organizational root. This is a PEN registered with IANA, per RFC 9371.
Note that not all OIDs listed below will be used - some only exist as data scheme padding or reservations.
...65394.10 - Certificate Operations
...65394.10.2 - Custom fields for use in DNs
...10.2.1 - Fields pertaining to all XIVAuth-issued certificates....10.2.2 - Fields pertaining to XIVAuth-issued character certificates.
...2.2.1 - The Lodestone ID of this character....2.2.2 - The Persistent Key of this character registration....2.2.3 - The Content ID of this character (if confirmed)...2.2.4 - The SE Account ID of this character (if confirmed)...10.2.3 - Fields pertaining to XIVAuth-issued user certificates....65394.10.3 - Custom EKUs on certificates.
...10.3.1 - CharacterAuthentication, indicating this certificate may be used to authenticate a character.