uXXXX

UXXXX is a placeholder label used in technical writing to represent a four-digit hexadecimal identifier. The closest formal reference is the Unicode notation U+XXXX, which denotes a Unicode code point where XXXX is a hexadecimal value. For example, U+0041 represents the Latin capital letter A. In informal contexts, UXXXX may appear as an abstract example without implying a specific code point or value.

In software development and data schemas, UXXXX can indicate an unsigned hexadecimal value with four digits. It is not a term for a specific technology, product, or organization. When encountered in documentation, the exact interpretation of UXXXX depends on the surrounding context—whether it denotes a Unicode code point, a placeholder for an identifier, or a sample value in a schema. If a document uses UXXXX in a particular meaning, that meaning should be defined within that document or its glossary. See also Unicode, hexadecimal, and code point notation.