Yiic creates .yii files

After running "yiic webapp x", the x directory contains quite a few files named .yii.

I havent found anything about what their purpose is, looked both on the web and grep'd through the source code.

So, I ask: Whats their purpose and/or can they be removed ?

It would be good they would contain even just one line of text, explaining their purpose.

They are there to prevent some empty directories (e.g. assets, runtime) from being dropped when you deploy your application. They are not required, though, if your OS doesn't have this problem.