Case variants of IPA letters

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 ʔ and pharyngeal ʕ, both uppercase ⟨Ɂ⟩, ⟨꟎⟩ and lowercase ⟨ɂ⟩, ⟨꟏⟩ 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 ⟨Ɔ ɔ⟩, open e ⟨Ɛ ɛ⟩, and eng ⟨Ŋ ŋ⟩ are found, but others occur. Kabiyé of northern Togo, for example, has ⟨Ɔ ɔ, Ɛ ɛ, Ɖ ɖ, Ŋ ŋ, Ɣ ɣ, Ʊ ʊ⟩ (or ⟨Ʋ ʋ⟩), as in this newspaper headline:

MBƱ AJƐYA KIGBƐNDƱƱ ŊGBƐYƐ KEDIƔZAƔ SƆSƆƆ TƆM SE.

Some of the IPA letters that were adopted into language orthographies have since become obsolete in the IPA itself.