Avon wrote to All <=-
Just wanted to post something that used that word again... :)
Could be a drink I guess, or something that dropped in the mud and made that sound :)
https://www.landley.net/history/mirror/jargon.html#plonk
plonk excl.,vt.
[Usenet: possibly influenced by British slang 'plonk' for cheap booze, or 'plonker' for someone behaving stupidly (latter is lit. equivalent to Yiddish 'schmuck')] The sound a newbie makes as he falls to the bottom of a kill file. While it originated in the newsgroup talk.bizarre, this term (usually written "*plonk*") is now (1994) widespread on Usenet as a form of public ridicule. 
... Lots of people make sense, I want to make $$$
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