Max Overflow

[zx50]

Has anyone got any idea what max overflow means, here's what i think. I think it means, when you set the max overflow for undersized or oversized scenes then i think that you are allowing the codec to eat into the scene to put bits into it, in other words to make it simpler the codec can go mad with the bits when it has to and not when it does'nt need to,because i WAS encoding with them both set onto 1% but when i had them up to the maximum 80% the picture looked better whether it was just me or what i don't know, but anyway thats what i want to know, what does max overflow and max degration mean (i did'nt mention that bit before), thanks in advance!!