(Unicode) Private Use Areas

I thought this was of interest after I read this on SU:

https://superuser.com/questions/1205451/how-can-i-display-th...

Apple, apparently, has a private use area that defines things such as the Apple logo in Unicode; people on Apple platforms were unaware that it only displays on Apple hardware. I wasn't aware Unicode even had such a thing.

To me it opens up all kinds of interesting things - as a commenter in the SU question points out, nothing stops say, Microsoft, from defining the same code point as the Windows logo.