There are two types of addresses that don't exist. Those that are invalid as an address, and those that are valid as an address but aren't controlled by anyone.
Are there not properly three types?
I thought that some alt-coin had an issue with pre-mining, such that the owner decided to evidence his destroying the coins by sending to an address that was valid but *could not* be controlled by anyone; a /dev/null blackhole, as opposed obviously to those valid addresses that simply are not controlled at the moment but could be.
..or does Bitcoin not have the same equivalent /dev/null address?