U0090

U0090 typically refers to the Unicode code point U+0090, a control character in the C1 control set. Its official name is the Padding Character (PAD). It is a non-printable character and has no visible glyph in standard fonts. In Unicode data it is classified as a general category Cc (control) with a bidi class of BN (boundary neutral), reflecting its role in legacy text processing rather than as a printable symbol.

In terms of encoding, U+0090 is represented in UTF-8 as the two-byte sequence 0xC2 0x90. In legacy encodings such as Windows-1252, the byte 0x90 maps to U+0090 and is treated as a non-printing control character rather than a visual character. Because it serves as a control code, many text-processing environments strip or ignore it, and some contexts may handle it as a formatting or padding instruction depending on the protocol in use.

Usage and considerations: U+0090 has limited contemporary use in regular text. It is primarily of interest in the study of Unicode control characters, data interchange formats, and legacy systems where padding or synchronization markers were needed. In most modern programming languages and data formats, it is treated as a non-printing control and is generally omitted from displayed content. When debugging or parsing binary streams that include C1 controls, U+0090 may appear as a control sequence that requires context-specific handling.

See also: Unicode control characters, C1 controls, U+0080 to U+009F range, PAD.

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