Here is another idea for a sentence end punctuation. I call it the ambiguity mark. It is perhaps not as necessary as the irony mark; but unlike the irony mark, it has an elegant design.
I found this symbol in G.G. Neill Wright’s 1952 book The Writing of Arabic Numerals. It was written by a Papal Chancery hand of the 15th century and may plausibly be interpreted as 0, 3, 6, 7, or 8.
When would one use the ambiguity mark? It’s not intended for unintentionally ambiguous writing, as it would be better for the author to rewrite the sentence. The most compelling use would be for puns. Here is a classic font pun:
A font walks into a bar; and the bartender says: “We don’t serve your type here”
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