Different typefaces, character encodings and computer languages use various encodings and glyphs for quotation marks. This article lists some of these glyphs along with their Unicode code points and HTML entities. The Unicode standard defines two general character categories, "Pi" (punctuation initial quote) and "Pf" (punctuation final quote), for all quotation mark characters.
Contents |
"Ambidextrous" quotation marks were introduced on typewriters to reduce the number of keys on the keyboard, and were inherited by computer keyboards and character sets. Some computer systems designed in the past had character sets with proper opening and closing quotes. However, the ASCII character set, which has been used on a wide variety of computers since the 1960s, only contained straight single quote and apostrophe (', U+0027) and double quote (" U+0022).
Many systems, like the personal computers of the 1980s and early '90s, actually drew these quotes like curved closing quotes on-screen and in printouts, so text would appear like this (approximately):
”Good morning, Dave”, said HAL.’Good morning, Dave’, said HAL.These same systems often drew the grave accent (`, U+0060) as an open quote glyph (actually a high-reversed-9 glyph, to preserve some usability as a grave). This gives a proper appearance at the cost of semantic correctness. Nothing similar was available for the double quote, so many people resorted to using two single quotes for double quotes, which would look like the following:
‛‛Good morning, Dave’’, said HAL.‛Good morning, Dave’, said HAL.The typesetting application TeX still uses this convention for input files. However, the appearance of these characters has varied greatly from font to font. On systems which provide straight quotes and grave accents like most do today (and as Unicode specifies) the result is poor as shown here:
``Good morning, Dave'', said HAL.`Good morning, Dave', said HAL.The Unicode slanted/curved quotes described below are shown here for comparison:
“Good morning, Dave”, said HAL.‘Good morning, Dave’, said HAL.English curved quotes, also called “book quotes” or “curly quotes”, resemble small figures six and nine raised above the baseline (like 6...9 and 66...99), but then solid, i.e., with the counters filled. In many typefaces, the shapes are the same as those of an inverted (upside down) and normal comma. They are preferred in formal writing and printed typography.
In e-mail and on Usenet, curved quotes can only be used by using a MIME type with a character set outside of the ISO-8859 series such as a Unicode encoding or one of the Windows-125x series. In most cases, (the exceptions being if UTF-7 is used or if the 8BITMIME extension is present), this also requires the use of a content-transfer encoding. A few mail clients send curved quotes using the windows-1252 codes, but mark the text as ISO-8859-1, causing problems for decoders that do not make the dubious assumption that C1 control codes in ISO-8859-1 text were meant to be windows-1252 printable characters.
Curved and straight quotes are also sometimes referred to as smart quotes (“…”) and dumb quotes ("…") respectively; these names are in reference to the name of a function found in several word processors that automatically converts straight quotes typed by the user into curved quotes. This function, known as “educating quotes”, was developed for systems that lack separate open- and close-quote keyboard keys.
Supporting curved quotes has been a problem in information technology, primarily because the widely used ASCII character set did not include a representation for them (as discussed above).
Word processors have traditionally offered curved quotes to users, because in printed documents curved quotes are preferred to straight ones. Before Unicode was widely accepted and supported, this meant representing the curved quotes in whatever 8-bit encoding the software and underlying operating system were using—but the character sets for Windows and Macintosh used two different pairs of values for curved quotes, and ISO 8859-1 (historically the default character set for the Unixes and older Linux systems) has no curved quotes, making cross-platform compatibility quite difficult to implement.
Compounding the problem is the “smart quotes” feature mentioned above, which some word processors (including Microsoft Word and OpenOffice.org) use by default. With this feature turned on, users may not have realised that the ASCII-compatible straight quotes they were typing on their keyboards ended up as something entirely different.
Further, the “smart quotes” feature converts opening apostrophes (such as in the words ’tis, ’em, and ’til) into opening single quotation marks—essentially upside-down apostrophes. A blatant example of this error appears in the advertisements for the television show ‘Til Death.
Unicode support has since become the norm for operating systems. Thus, in at least some cases, transferring content containing curved quotes (or any other non-ASCII characters) from a word processor to another application or platform has sometimes been less troublesome, provided all steps in the process (including the clipboard if applicable) are Unicode-aware. But there are many applications which still use the older character sets, or output data using them, and thus problems still occur.
There are other considerations for including curved quotes in the widely used markup languages HTML, XML, and SGML. If the encoding of the document supports direct representation of the characters, they can be used, but doing so can result in difficulties if the document needs to be edited by someone who is using an editor that cannot support the encoding. For example, many simple text editors only handle a few encodings or assume that the encoding of any file opened is a platform default, so the quote characters may appear as “garbage”. HTML includes a set of entities for curved quotes: ‘ (left single), ’ (right single), ‚ (low 9 single), “ (left double), ” (right double), and „ (low 9 double). XML does not define these by default, but specifications based on it can do so, and XHTML does. In addition, while the HTML 4, XHTML and XML specifications allow specifying numeric character references in either hexadecimal or decimal, SGML and older versions of HTML (and many old implementations) only support decimal references. Thus, to represent curly quotes in XML and SGML, it is safest to use the decimal numeric character references. That is, to represent the double curly quotes use “ and ”, and to represent single curly quotes use ‘ and ’. Both numeric and named references function correctly in almost every modern browser. While using numeric references can make a page more compatible with outdated browsers, using named references are safer for systems that handle multiple character encodings (i.e. RSS aggregators and search results).
| View | Code | Unicode name | HTML | Comments |
|---|---|---|---|---|
| " | U+0022 | Quotation mark | " | Typewriter (“programmer’s”) quote, ambidextrous |
| ' | U+0027 | Apostrophe | ' | Typewriter (“programmer’s”) straight single quote, ambidextrous |
| « | U+00AB | Left-pointing double angle quotation mark | « | Double angle quote (chevron, guillemet, duck-foot quote), left |
| » | U+00BB | Right-pointing double angle quotation mark | » | Double angle quote, right |
| ‘ | U+2018 | Left single quotation mark | ‘ | Single curved quote, left |
| ’ | U+2019 | Right single quotation mark | ’ | Single curved quote, right |
| ‚ | U+201A | Single low-9 quotation mark | ‚ | Low single curved quote, left |
| ‛ | U+201B | Single high-reversed-9 quotation mark | ‛ | also called single reversed comma, quotation mark |
| “ | U+201C | Left double quotation mark | “ | Double curved quote, or “curly quote”, left |
| ” | U+201D | Right double quotation mark | ” | Double curved quote, right |
| „ | U+201E | Double low-9 quotation mark | „ | Low double curved quote, left |
| ‟ | U+201F | Double high-reversed-9 quotation mark | ‟ | also called double reversed comma, quotation mark |
| ‹ | U+2039 | Single left-pointing angle quotation mark | ‹ | Single angle quote, left |
| › | U+203A | Single right-pointing angle quotation mark | › | Single angle quote, right |
| 「 | U+300C | Left corner bracket | 「 | CJK |
| 」 | U+300D | Right corner bracket | 」 | CJK |
| 『 | U+300E | Left white corner bracket | 『 | CJK |
| 』 | U+300F | Right white corner bracket | 』 | CJK |