A stray "J" I encountered years ago: a certain client's support tickets would often end with a single "J", which was a little confusing as it was not one of their name initials. After a brief investigation, the original email source contained this:
<font face="Wingdings">J</font>
On seeing just the title, before reading the article, I assumed it was about the Wingdings J.
Seemed to be a common occurrence from Microsoft Outlook users.
I remember discovering this in about 2010, and thought it was hilarious