Asterisk Operator ∗

The Asterisk Operator character (∗) is a standard HTML entity defined in the HTML specification. In HTML source code, it can be written using the named entity reference ∗, the decimal numeric character reference ∗, or the hexadecimal numeric reference ∗. The character is assigned Unicode code point U+2217 in the Universal Character Set.

The asterisk operator (∗) is a mathematical variant of the asterisk used as a convolution operator, multiplication symbol in some notations, and footnote marker. It is distinct from the keyboard asterisk (*) and is centered vertically for use in mathematical expressions alongside other operators.

Symbol entities encompass a wide variety of special characters used in legal disclaimers, intellectual property notices, typographic ornaments, card suit indicators, and miscellaneous notation throughout web content. These characters appear in website footers for copyright notices, product pages for trademark symbols, academic papers for dagger footnote markers, and decorative or gaming contexts for card suits and stars.

When deciding how to encode the Asterisk Operator character in your HTML documents, the named entity ∗ is generally the most readable choice for developers reviewing or maintaining source code. The decimal form ∗ and hexadecimal form ∗ 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 asterisk operator in mathematical notation for convolution, the Hodge dual, and contexts where a vertically centered asterisk is needed. For footnotes in general text, the standard keyboard asterisk suffices. The mathematical variant ensures proper alignment with other mathematical operators.