By reference to which

Not a synonym for “on”. A prepositional phrase with a subtle bearing, well illustrated by the 2010 GMSLA’s definition of Income Record Date.

Income Record Date, with respect to any Securities or Collateral, means the date by reference to which holders of such Securities or Collateral are identified as being entitled to payment of Income;

Not the date on which Income is paid, but the date on which you had to be holding securities to become entitled to payment.

See also