When you want to retire, sell or give away a Mac, you should never just pass it on to someone else as-is.
There are many apps that only allow you to use your serial numbers a limited time, most notably from Adobe and Microsoft. You should deactivate the software so that you can reuse your serial numbers on a new Mac.
There's other data you should save and remove also. In his article "iCloud services can make decommissioning your Mac more complicated," our good friend David Morgenstern at The Apple Core on ZDNet alerts us to an update to an Apple support article that deals with just that issue.
The first c
