Insular and Celticist letters
Orthographic letters for glottals
Additions for Lithuanian dialectology
Letters for Middle Vietnamese
Archaic letters for Volapük
Letters for pre-1921 Latvian orthography
Letter for West African languages
Letter for Japanese phonemic transcription
Letters for Americanist orthographies
Letter for African languages
Letter for German dialectology
Letters for African languages
Letters for Mazahua (Mexico)
Letters for Ugaritic and Egyptological transliteration
Letters used in early Pinyin romanization
Additional letters for Gaulish
Ancient Gaulish and Celtic epigraphic letters
Additions for Extended IPA
Ancient Roman epigraphic letters