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Real Symbols, Not ASCII Look-alikes

SHOULD

SHOULD: Use real typographic symbols, not ASCII look-alikes: × (U+00D7) for multiplication not the letter x, − (U+2212) for minus not a hyphen, and © ™ ® not (c) / (TM) / (R). The substitutes read as unfinished and can be ambiguous in data and dimensions.

Use ×, −, © ™ ® for multiplication, minus, and marks — not the letter x, a hyphen, or (c) / (TM) / (R)

1920 × 1080   {/* not 1920 x 1080 */}
−40°C         {/* U+2212, not a hyphen */}
© 2026 · Pro™

Bad

Good

Why it matters

The letter x is not a multiplication sign, a hyphen is not a minus, and "(c)" is not a copyright symbol — they are ASCII stand-ins from an era of 95 printable characters, and Unicode retired the excuse decades ago. "1920 x 1080" should be "1920 × 1080" (× is `×` / U+00D7); "-40°" should carry a real minus "−40°" (− is U+2212, which has the correct width and, unlike a hyphen, will not line-break away from its number); and (c) / (TM) / (R) should be © ™ ® (`©` `™` `®`).

The substitutes are legible but read as unfinished, and in dimensions or data they are genuinely ambiguous — is "2 x 3" a product or a variable named x? This is the same rule as content-typographic-quotes and content-ellipsis-character, just the less-remembered corner of it: reach for the character that was designed for the job, not the one that happened to be on a 1970s keyboard.

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.