Twitter ratio - restrictions?

One of my new twitter contacts mentioned that there is a 'secret twitter ratio' causing certain restrictions - but I do not really know what it means? Is Twitter restricting the amount of friends or followers? I looked for the info on different blogs writing about Twitter ratio (ratio of our Twitter followers to our friends) but I cannot see this being mentioned:/
Actually the ratio and its connection to human behaviour idea does reflect mine. I agree that some of use Twitter to chat, some to network, some to do it all and to gather knowledge.
Here's my official Twitter ratio:
To quote Scoble, I belong to those who 'want to learn more' which perfectly matches my intentions:)

I would like to know thought if there are any rules connected to the Twitter ratio which might affect my account...