@silverpill @hongminhee FEP-e232 is a standardized generic framework for microsyntaxes including, but not limited to, "quotes", but does it standardize any concrete link relation for quoting? The convention to use `https://misskey-hub.net/ns/ as the `rel` value isn't standardized by the FEP nor Misskey Hub, I think?
Also, note that Misskey doesn't support it (both incoming and outgoing), so its support isn't overwhelming yet number-of-end-users-wise (Misskey happens to have the second largest server in the Fediverse)