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contentimpeccable

Em-Dashes Are an AI Tell

SHOULD

SHOULD: Punctuate with commas, colons, semicolons, periods, or parentheses instead of em-dashes (and never the ASCII `--`) — 5 or more in body text is a machine-written cadence readers register even when each individual dash is defensible.

Punctuate with commas, colons, semicolons, periods, or parentheses instead of em-dashes

Bad

Good

Why it matters

The skill itself bans the em dash outright, but its detector is deliberately lenient: it only fires at 5 or more em-dashes (or the ASCII `--`) in body text. Be accurate about that distinction. A single dash is a style choice; a page where every paragraph pivots on the same mid-sentence interruption has a machine-written cadence, and it is the cadence readers register, not any individual mark. Repunctuating forces you to pick the mark that actually carries the relationship, which varies the rhythm as a side effect.

References

Built by Gleb Stroganov, design engineer at Evil Martians.

The rules come from other people's skills and guidelines — Vercel, Rauno Freiberg, @Ibelick, impeccable, Emil Kowalski, Tailwind, RAMS — each one credited on the Sources page. The work here is extraction and wiring: every rule is pulled into one corpus, given a good and a bad example you can operate, a MUST/SHOULD/NEVER rule an agent can paste, and a link back to where it came from.