Ksi is a letter of the early Cyrillic alphabet

Early Cyrillic alphabet

The Early Cyrillic alphabet is a writing system developed in the First Bulgarian Empire in the 9th or 10th century to write the Old Church Slavonic liturgical language...

, derived from the Greek

Greek language

Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...

 letter Xi (Ξ, ξ). It was mainly used in Greek loanwords, especially words relating to the Church.

Ksi was eliminated from the Russian alphabet

Russian alphabet

The Russian alphabet is a form of the Cyrillic script, developed in the First Bulgarian Empire during the 10th century AD at the Preslav Literary School...

 along with psi

Psi (Cyrillic)

Psi is a letter in the early Cyrillic alphabet, derived from the Greek letter psi . It represents the sound /ps/, as in English naps...

, omega

Omega (Cyrillic)

Omega is a letter used in the early Cyrillic alphabet. Its name and form are derived from the Greek letter Omega .Unlike Greek, the Slavic languages had only a single /o/ sound, so Omega was little used compared to the letter On , descended from the Greek letter Omicron...

, and yus

Yus

Little Yus and Big Yus , or Jus, are letters of the Cyrillic script, representing two Common Slavonic nasal vowels in the early Cyrillic and Glagolitic alphabets. Each can occur in iotified form , formed as ligatures with the letter Decimal I...

 in the Civil Script of 1708 (Peter the Great

Peter I of Russia

Peter the Great, Peter I or Pyotr Alexeyevich Romanov Dates indicated by the letters "O.S." are Old Style. All other dates in this article are New Style. ruled the Tsardom of Russia and later the Russian Empire from until his death, jointly ruling before 1696 with his half-brother, Ivan V...

's Grazhdanka), and has also been dropped from other secular languages.

It represented "60" if used as a number.

Computing codes

character
Unicode name	CYRILLIC CAPITAL LETTER KSI		CYRILLIC SMALL LETTER KSI
character encoding	decimal	hex	decimal	hex
Unicode Unicode Unicode is a computing industry standard for the consistent encoding, representation and handling of text expressed in most of the world's writing systems...	1134	046E	1135	046F
UTF-8 UTF-8 UTF-8 is a multibyte character encoding for Unicode. Like UTF-16 and UTF-32, UTF-8 can represent every character in the Unicode character set. Unlike them, it is backward-compatible with ASCII and avoids the complications of endianness and byte order marks...	209 174	D1 AE	209 175	D1 AF
Numeric character reference Numeric character reference A numeric character reference is a common markup construct used in SGML and other SGML-related markup languages such as HTML and XML. It consists of a short sequence of characters that, in turn, represent a single character from the Universal Character Set of Unicode...	Ѯ	Ѯ	ѯ	ѯ