The ʻokina, also called by several other names (see examples below), is a unicameral consonant letter used within the Latin script to mark the phonetic glottal stop, as it is used in many Polynesian languages.

In 1995 the United States Board on Geographic Names began changing its longtime policy and is now using ʻokina and kahakō in the Geographic Names Information System.

In plain ASCII the glottal is sometimes represented by the apostrophe character ('), ASCII value 39 in decimal and 27 in hexadecimal, which in most fonts currently used renders as a straight, data-processing, typewriter apostrophe as is also specified in Unicode. But in some older fonts, especially those used on Unix-like platforms and related platforms and on an MS-DOS screen, it renders as a right single quotation mark (which is the wrong shape).

A "hypercorrect"^{[citation needed]} (that is, incorrect) method for plain ASCII text is to use U+0060 grave accent (`) (called a "back-quote" character), which in some older fonts does display a glyph similar to a left single quotation mark. However, in most newer fonts, it has a pronounced lean to the left and can look inappropriate. A (partial) advantage is when a wordlist is alphabetically sorted, the "`" often comes after the "z", exactly where it should be in the Tongan language (admittedly not so in most other Polynesian languages, where it should be ignored for purposes of sorting). It is still useful as a fallback when words are to be entered into a database with limited character-set ability to have the character distinct from the apostrophe.