Although most people use the term "typo" to refer to any mis-pressed key in text product (often mis-spellings), Receding Hairline discusses ten typos that fall more squarely in the realm of typography: includes both usage rules and keystroke combinations for the obvious smart/typographer quotes, but also lesser-known degree symbols, true ellipses, straight quotes for measurements, hyphens, fractions, and the interpunct.

[via Lifehacker]