Some obscure unicode character U+FFFC, represented in the url bar as the %-escaped sequence of the bytes of its utf-8 encoding. https://en.wikipedia.org/wiki/S

Some obscure unicode character U+FFFC, represented in the url bar as the %-escaped sequence of the bytes of its utf-8 encoding. https://en.wikipedia.org/wiki/Specials_(Unicode_block) https://en.wikipedia.org/wiki/Specials_(Unicode_block) No idea where it comes from, but it randomly peppers some people's comments and posts for no obvious reason: https://hn.algolia.com/?query=%EF%BF%BC https://hn.algolia.com/?query=%EF%BF%BC I'll paste one here between double quotes: " ". To me, it shows up variously as either "[obj]" or as invisible whitespace. edit: It doesn't work -- HN removes that unicode character. (It filters out large ranges, particularly emojis). So how the heck did it get in those peoples' comments?