ӏ

From the Roman numeral I that was furnished on most Russian manual typewriters. This letter also did duty for the numeral 1.

ӏ

1. palochka (the name of this letter in English)
2. The fifty-third letter of the Kabardian Cyrillic alphabet. It also provides the first or second component in a number of Kabardian digraphs and trigraphs. Its Kabardian name is ’ə and it represents a glottal stop or an ejective consonant. It is preceded by я and followed by the digraph ӏу. Example: ищӏэн (jəɕʼán, “he knew it”).
3. In the Avar Cyrillic alphabet, it is not an independent letter, but is combined with various consonants, such as гӏ, кӏ, лӏ, тӏ, хӏ, цӏ, чӏ (pronounced ʕ, kʼ, tɬʼ, tʼ, ħ, t͡sʼ, and t͡ʃʼ).
4. The palochka is also found in the Cyrillic alphabets of Abaza, Adyghe, Chechen, Dargwa, Ingush, Lak, Lezgi, and Tabasaran.

Often the capital Roman letter I or the numeral 1 is used instead of the Ӏ symbol. In some of these languages, such as Chechen, national keyboards still do not provide the Ӏ symbol, and the Roman letter or the numeral are in standard use.

• Wikipedia article on the palochka
• Wikipedia article on the Cyrillic alphabet