@Quasirandom
making it obvious you can't be blocked, but it does appear next to mine.
It's due to caching.
I could create the files without an icon next to my own nick name, because nobody should be able to block me.
However, for everybody else, I either turn off all caching (to show each person a custom version of the page without the icon next to their own name), slowing the forum quite a bit and putting a bigger CPU load on the servers, or I keep the block icon next to everybody's name and catch the self block on the back end.
Although, I may put in more effort into the javascript and add code that would remove the icon from the user's own posts. That would require more effort and for now I've given it way more than it warrants. Just for the record, so far, 5 people have use the feature and all of the blocked that exact same person.
We'll see in a week or two if the effort I put in was worth it or not. Although, I suspect not. Most people on the forum are pretty civilized and are generally nice, so nobody asked for the ability to block before now despite the forum using my own code since 2015.