Cook up 13.3 or keep dreaming?

Is it about the 10..15nF capacitor in the circuit diagram ???

•Some critical electric parts can be any value within their range: capacitor from 10 nF to 15 nF, inductor from 1 uH to 2.2 uH can be used (software will handle these values)

I just saw this strange 13.3 nF value in that mailto : link

And I'm not sure if this "250V" is a real requirement, too.