This code point is invisible, reserved, private-use, or a control. The dot is a placeholder, not its glyph.

U+0015

NEGATIVE ACKNOWLEDGE

General category
Control Cc
Unicode block
Basic Latin
Combining class
0
Bidirectional class
BN
Mirrored
No

U+0015 NEGATIVE ACKNOWLEDGE is a Unicode 16.0.0 character in the Control category. It belongs to the Basic Latin block.

Encodings & representations

Choose the representation you need, then copy its value.

Code point

U+0015

Decimal value

21

HTML decimal reference



HTML hexadecimal reference



UTF-8 bytes (hex)

15

UTF-16 code units (hex)

0015

UTF-32 code unit (hex)

00000015

URL percent-encoded UTF-8

%15

C# Unicode escape

\u0015

JavaScript Unicode escape

\u0015

JSON Unicode escape

\u0015

CSS Unicode escape (trailing space)

\0015

ASCII position (7-bit)

21 (0x15)

ISO-8859-1 position (Latin-1)

21 (0x15)

Windows-1252 position

21 (0x15)
About these encodings
  • ASCII positions run from 0 to 127. Position cards show the decimal byte value followed by hexadecimal.
  • “Extended ASCII” is not a single encoding. ISO-8859-1 (Latin-1) and Windows-1252 are shown separately; they differ at bytes 128–159. Windows-1252 leaves five of those bytes undefined.
  • Legacy position cards appear only when the character has an exact mapping. For example, the euro sign is Windows-1252 byte 128 (0x80), but has no ASCII or Latin-1 position. A legacy byte is not necessarily the Unicode code point or its UTF-8 encoding.
  • Percent encoding lists every UTF-8 byte; URL-safe characters do not normally need encoding.
  • JSON escapes omit the surrounding quotes.
  • UTF code units are not byte-order-specific.
  • HTML parsers remap numeric references for U+0000 and some control characters, so these may not round-trip.