Rushmore, that's against the 200% rule.
I always make sure that it's never more than 210%.
And, I only do it on routes that no one could possibly compete. For example, in AC, I'm flying a 735 from Las Palmas to JFK. Now, I'm hovering right around 200% of demand, but who would be crazy enough (other than me) to run a half-full BABY 737 from NY to the Canary Islands.
Another example from my MT2 airline is the little routes I serve with my DH8s. I sometimes oversupply the domestic routes by as much as 400%. But since I'm the only airline in Bolivia, I'm the only one who has the possibility to fly those routes.
A third example is GCLP to Minsk, Belarus in AC. I have a 735 running just at 200% of demand, but no one is based in Belarus, and I am the only one in Las Palmas. So no one cares.
But I would never oversupply a Dublin route in AC, for example. And I don't (with the possible exception of Halifax, but that's unprofitable for me, anyway.)