I know that
/etc/apt/sources.list is used to tell the apt ubuntu/debian package system about the packages it should use. This is quite clear already.
But I have seen that there is a file
/etc/apt/sources.list.apt-clone and I was wondering what it is? Is this file only present on my system (which is 12.04 precise)?
It seems indeed to be a copy of the file
In case the file exists in all 12.04 versions, what purpose does it serve?