This is a neat trick and reminds me of MCI codes from the BBS days. Basically, for a lot of BBS software (and usually enabled by default) visitors to your BBS when posting in discussion threads could insert escape characters (like "%UN") which at runtime would be replaced with metadata related to the person viewing the post at that time.
So, if I were to post "%UN's mother was a hamster and father smelled of elderberries" as part of a thread when I viewed it it would say "gfodor's mother..." etc. You could have first name, last name, etc, so with some creative thinking you could post fairly convincing posts that would trick people into thinking you were actually legitimately mentioning them.
I can remember many posts filled with angry replies from random users who went off the deep end when seeing that some random person on the BBS was trash talking them personally. Oops.
Edit: And for the curious, the purpose of these codes was usually for people creating assets for the BBS. For example, when designing your home screen (an ANSI text file, basically), inserting the codes made it so the home screen would reflect information on the logged in user. Usually when enabled the interpolation happened anywhere, not just in user defined assets. (Of course as BBS software got more mature these types of pranks were not possible with default settings.)
My favorite BBS hack was that on some standard RA configs, unless explicitly turned off by the sysop, you could save received messages to disk even if you were just a normal user. This meant that you could send a message to yourself, i.e. 'del . /q /s' (or whatever zapped your dos disk, I can't really remember.), and then save it to 'c:\autoexec.bat' ...
Other fun things where nailbombs, small .zip files that would expand to multiple gigs. When you uploaded those to early RA systems the virus scanner would attempt to unpack them and quickly fill up the entire disk, causing the BBS to grind to a halt.
So, if I were to post "%UN's mother was a hamster and father smelled of elderberries" as part of a thread when I viewed it it would say "gfodor's mother..." etc. You could have first name, last name, etc, so with some creative thinking you could post fairly convincing posts that would trick people into thinking you were actually legitimately mentioning them.
I can remember many posts filled with angry replies from random users who went off the deep end when seeing that some random person on the BBS was trash talking them personally. Oops.
Edit: And for the curious, the purpose of these codes was usually for people creating assets for the BBS. For example, when designing your home screen (an ANSI text file, basically), inserting the codes made it so the home screen would reflect information on the logged in user. Usually when enabled the interpolation happened anywhere, not just in user defined assets. (Of course as BBS software got more mature these types of pranks were not possible with default settings.)