Cuatrillo
Cuatrillo (capital: Ꜭ, small: ꜭ) (Spanish for "little four") is a letter of several colonial Mayan alphabets in the Latin script that is based on the digit 4. It was invented by a Franciscan friar, Alonso de la Parra, in the 16th century to represent the velar ejective consonant /kʼ/ found in Mayan languages, and is known as one of the Parra letters.
A derivative of the cuatrillo by adding a comma diacritic, Ꜯ ꜯ was used for the alveolar ejective affricate /tsʼ/ found in the same languages.
The cuatrillo is encoded in Unicode at the code points U+A72C Ꜭ LATIN CAPITAL LETTER CUATRILLO and U+A72D ꜭ LATIN SMALL LETTER CUATRILLO, respectively. The cuatrillo-commas are at U+A72E Ꜯ LATIN CAPITAL LETTER CUATRILLO WITH COMMA and U+A72F ꜯ LATIN SMALL LETTER CUATRILLO WITH COMMA.