Greek Capital Letter Iota Ι

The Greek Capital Letter Iota character (Ι) is a standard HTML entity defined in the HTML specification. In HTML source code, it can be written using the named entity reference Ι, the decimal numeric character reference Ι, or the hexadecimal numeric reference Ι. The character is assigned Unicode code point U+0399 in the Universal Character Set.

Greek capital iota is visually identical to the Latin capital letter I. It is the ancestor of the Latin I and appears primarily in Greek-language text. The lowercase ι is occasionally used in mathematical contexts.

Greek letter entities are indispensable for scientific papers, engineering documentation, statistical analyses, and mathematical content published on the web. From physics equations using alpha and omega to statistical formulas featuring sigma and mu, these entities allow content authors to include Greek characters reliably without requiring specialized fonts or complex Unicode input methods on the keyboard.

When deciding how to encode the Greek Capital Letter Iota character in your HTML documents, the named entity Ι is generally the most readable choice for developers reviewing or maintaining source code. The decimal form Ι and hexadecimal form Ι are equally valid alternatives that work in contexts where named entities may not be supported, or when generating HTML output programmatically from server-side code. All three representations produce identical visual output in every modern web browser.

Use the capital iota entity in Greek-language text, linguistic discussions, and complete Greek alphabet displays. In mathematical and scientific notation, the lowercase iota is preferred when a Greek iota is needed.