With the adoption of letters from the International Phonetic Alphabet (IPA) in various national alphabets, letter case forms have been developed. This usually means capital (uppercase) forms were developed, but in the case of the glottal stop and pharyngeal , both uppercase , and lowercase , are used.
The adoption of IPA letters has been particularly notable in Sub-Saharan Africa, largely due to the Africa Alphabet. In languages such as Hausa, Fula, Akan, Gbe languages, Manding languages, and Lingala, casing pairs of IPA letters such as open o , open e , and eng are found, but others occur. Kabiyé of northern Togo, for example, has (or ), as in this newspaper headline:
Some of the IPA letters that were adopted into language orthographies have since become obsolete in the IPA itself.
The chart below provides IPA letters (other than those of the English alphabet) and their capital forms. Two of these capitals have distinct lowercase forms, because the IPA letters (ÃÂ and ÃÂ) are unicameral in some orthographies and bicameral in others.
Sources may differ in the graphic form of the capital letter; where these are corresponding characters in Unicode, only one will be encoded as a casing pair with the IPA letter. If casing is to be maintained, the other form will need to be accessed as a character variant in the font rather than through the dedicated Unicode character.
Capitals of obsolete IPA symbols are:
For some IPA letters that do not have Unicode-supported capitals, there may be a mathematical symbol or letter in a non-Latin script that coincidentally resembles the expected capital letter. However, it is unlikely such pairings will work reliably across fonts. Examples are: