In the days of printing with metal type sorts, it was common to rotate letters and digits 180° to create new symbols. This was a cheap way to extend the alphabet that didn't require purchasing or cutting custom sorts. The method was used for example with the Palaeotype alphabet, the International Phonetic Alphabet, the Fraser script, and for some mathematical symbols. Perhaps the earliest instance of this that is still in use is turned e for schwa.

In the eighteenth-century Caslon metal fonts, the British pound sign (£) was set with a rotated italic uppercase J.^[1]

The following rotated (turned) letters have Unicode codepoints unless otherwise indicated.

In this table, parentheses mark letters that stand in for themselves or for another. For instance, a rotated 'b' would be a 'q', and indeed some physical typefaces didn't bother with distinct sorts for lowercase b vs. q, d vs. p, or n vs. u; while a rotated 's' or 'z' would be itself. Long s with a combining dot below, ⟨ſ̣⟩, can stand in for a rotated j.

(En dashes are used to mark small caps that would not be very distinct from the turned lower case letter, though they are possible: turned small cap c is supported, for example: ⟨ᴐ⟩).

The Fraser script creates a number of duplicates of the rotated capitals.

The Unicode characters ⅁, ⅂, ⅄ are specified as sans-serif. A normal turned Y, ⟨Ꟛ⟩, has been accepted for Unicode 16. Additional small cap forms are found in the literature (e.g. turned ᴀ ʟ ᴜ), but are not supported as of Unicode 15.

Other rotated letters include the digraphs ᴂ and ᴔ. The "rotated" capital Q in Unicode is only turned 90 degrees: ℺.

Many of the few rotated Greek letters are intended for mathematical notation. In this table, an en dash is used to mark Greek and Cyrillic letters that are not distinct from a Latin letter. Reversed L, ⟨⅃⟩, can stand in for a rotated gamma Γ, though Unicode defines it as sans serif.

⟨ƍ⟩ is close to the turned form of one variant of lower-case Б.

In some fonts, an allograph of Ʒ displays as turned Σ.

In addition, the horseshoe ʊ ᶷ of the IPA has allographs that are a turned small-capital Ω.

Other rotated symbols include ɞ (rotated or reversed ʚ), ʖ (rotated ʕ) ⱹ (rotated ɽ), ɺ (rotated ɼ), the digits ↊ and ↋, the insular g: Ꝿ ꝿ, and the ampersand ⅋.

The turned comma or inverted comma (‘) is, as its name suggests, a rotated comma. This symbol is most commonly encountered as an opening single quotation mark. It is also used for the Hawaiian letter ʻokina. In some older British texts, it was used as a superscript ⟨c⟩ to abbreviate for the Scottish name element Mac/Mc, also written as M^ac/M^c, thus yielding M‘, as in M‘Culloch.^[3]

Spanish uses the rotated punctuation marks ¡ (inverted exclamation mark) and ¿ (inverted question mark).

In addition to turned letters, Unicode supports a few reversed (mirror-image) letters such as ɘ, Ƨ ƨ, Ƹ ƹ, ʕ, ᴎ, ᴙ, ꟻ, ⅃ and ꟼ; Cyrillic Ԑ ԑ (reversed З з) and Ꙡ ꙡ (as well as Cyrillic И и and Я я, which are graphically equivalent to reversed Latin N ɴ and R ʀ), superscript ᶟ ᴻ, and the tresillo Ꜫ ꜫ, which historically is a reversed three. Current IPA ɜ is officially a reversed rather than rotated ɛ; the older rotated ᴈ is now deprecated. Lower-case Ƌ is close to a reversed Cyrillic capital Б. Reversed k ɡ ŋ (𝼃 𝼁 𝼇) were added to the extIPA in 2015.