Imitation is the sincerest form of flattery

2007: https://tools.ietf.org/html/rfc5105#section-7

The concept of the validation token may be useful in other registry-type applications where the proof of an underlying right is a condition for a valid registration.

An example is a Top Level Domain (TLD) where registration is subject to proof of some precondition, like a trade mark or the right in a name. Such situations often arise during the introduction of a new TLD, e.g., during a “sunrise” phase.

2013: https://tools.ietf.org/html/draft-lozano-tmch-smd-02

I thought the IETF discouraged re-inventing the wheel?