Inverted Interrobang

Paste this one into a document and there is a fair chance you get an empty rectangle. It lives in Supplemental Punctuation, a block most system fonts never bothered to cover; one survey of installed faces turns it up in fewer than sixty, and Arial, Helvetica, Calibri and Times New Roman are not among them. The mark itself works fine. The plumbing under it does not.

What it does is simple enough. It opens a sentence the way ¿ and ¡ do, for a sentence that will end in an interrobang — the same bracketing instinct, applied to a mark invented in the 1960s rather than one inherited from Latin. Unicode admitted it in version 5.1, in April 2008, fifteen years after the interrobang itself got in, and recorded an alternative name that is also the entire joke: the character database lists "gnaborretni", the mark's name spelled backwards, as a formal alias.

The awkwardness is that no orthography actually asks for it. Spanish is the language whose bracketing punctuation the design borrows from, and Spanish does not recognise the interrobang at all; when the Real Academia Española needs to punctuate something interrogative and exclamatory at once, it stacks the two marks it already has, ¿¡ at the front and !? at the back. English, which does use the interrobang here and there, has no opening-mark convention to hang this on. So the character is the logical completion of a rule that no writing system has ever applied to it — encoded because the shape follows, not because anyone was waiting.

That has not made it useless, only unofficial. It gets used to bracket a whole incredulous sentence in informal writing, and the pairing reads instantly even to someone meeting it for the first time, which is more than most invented punctuation manages. Getting one out of a keyboard: type 2E18 and press Alt+X in Microsoft Word, or use the numeric reference ⸘ in HTML. There is no named entity for it, and there never will be — the named set was closed long before anyone needed this.