⁓ (12. 484)

Although also slightly peeved that the em-dash has become the signature punctuation of artificial intelligence chatbots (see also, scroll down for an act of malicious non-compliance with an agent) and sad to see the way I write coopted—though maybe leaning too heavily on a brittle linkage and perhaps should rely more on brackets or the semicolon, I was naturally intrigued by this proposal for a separator available exclusively for human use to signal that it was not penned by machine, the am-dash, via Web Curios and as in cogito ergo sum. Superficially like the title swung dash (used primarily, however, to set apart a list of alternatives or approximates or in dictionary entries to avoid reprinting the term being defined), the am-dash would be but of a restricted character set—see also.
First widely used in the Nicholas Okes’ publication of Shakespeare’s plays to capture pauses, interruption and epiphany of the staged performances in the early seventeenth century, Jonathan Swift’s 1733 verse On Poetry later encapsulated the style as:

Blot out, correct, insert, refine,
Enlarge, diminish, interline;
Be mindful, when Invention fails;
To scratch your Head, and bite your Nails.

Your poem finish’d, next your Care
Is needful, to transcribe it fair.
In modern Wit all printed Trash, is
Set off with num’rous Breaks⸺and Dashes—

Much more at the links above.