@Red_Hat @matty @soapone :cirnolaughing:
It's old net jargon, but well documented.
Back in the day USENET was a if not the thing, it was a discussion forum kinda like Reddit but much, much better for a long time because of the sort of person you had to be to get access to a UNIX(TM) system.
It uses a flooding algorithm, meaning every site got every posting (later a cancel system was set up, plus the "USENET Death Penalty" which almost never happened but would remove a site from the net). Was the origin of "spam" as we use it today for unwanted emails etc.
So front ends for individual users got a "kill file" feature, muting/blocking people you didn't want to see any more. "Plonk" is fair notice you're adding someone to your's.
Note to @pyrate you're still following me because the latest generation of Pleroma's front end is buggy. :ms_pleroma: