Section 5.6 states:

To defeat induced linkability, clients MUST launch cover connections to ≥ 2 unrelated origins (non-HTX) within [0, 1 000 ms] of the retry; HTX start MUST be delayed by an additional [100, 700 ms] chosen independently.

However, there's no clear definition on what an "unrelated origin" should be, and how it is picked. If we want to leave this as an implementation detail, this will make different implementations of this aspect distinguishable, adding a data point for fingerprinting.