The General Alphabet of Cameroon Languages was created in the late 1970s as an orthographic system for all Cameroonian languages. Consonant and vowel letters are not to contain diacritics, though ⟨ẅ⟩ is a temporary exception. The alphabet is not used sufficiently for the one unique letter, for a bilabial trill, to have been added to Unicode.
Maurice Tadadjeu and Etienne Sadembouo were central to this effort.
** Like ⟨ɓ⟩, but with the top hook turned to the left.
Aspirated consonants are written ph, th, kh etc. Palatalized and labialized consonants are py, ty, ky and pw, tw, kw etc. Retroflex consonants are written either Cr or with a cedilla: tr, sr or ţ, ş, etc. Prenasalized consonants are mb, nd, ŋg etc. Preglottalized consonants are 'b, 'd, 'm etc. Geminant consonants are written double.
Long vowels are written double. Nasal vowels may be written with a cedilla: a̧ etc. or with a single following nasal consonant: aŋ etc. (presumably assimilating to any following consonant), in which case VN would be written with a double nasal: aŋŋ etc. Harmonic vowels are written with a sub-dot, as ⟨bibị⟩ for [bib-y].
Tone is written as in the IPA, with the addition or a vertical mark for mid-low tone: ⟨á ā a̍ à, â ǎ⟩ etc. Where rising and falling tones only occur on long vowels, they are decomposed: ⟨áà, àá⟩ etc. The high tone mark is used for contrastive stress in languages that do not have tone.