I. Sicrhau bod gwasanaeth digonol ar rai llwybrau llai poblogaidd ond strategol na fyddai’n bodoli fel arall o dan amodau’r farchnad agored.  Diffinio rhwymedigaethau gofynnol penodol.
I. Ensure adequate frequency on some thin, but strategic routes that would not otherwise exist under free market conditions.  Defining certain minimum obligations.