U+2415 "␕" Symbol for Negative Acknowledge Unicode Character

Unicode Version 17.0

U+2415 "␕" Symbol for Negative Acknowledge is a control code graphic used in computing and telecommunications to visually represent the ASCII control character NAK, which has a numerical value of 21. Originally defined in the C0 control code set, the NAK character was part of the early communication protocols for data transmission, where it indicated that the receiving device did not correctly receive the previous block of data and requested a retransmission. The graphic symbol itself, depicting the letters "NAK" enclosed in a single-line box, was introduced in Unicode to allow for the visible printing or display of this non-printable control code, making it useful in debugging, logging, and data analysis contexts where the actual control function needs to be represented as a tangible character.

General Properties

Code Point U+2415
Version Added 1.1
Name Symbol for Negative Acknowledge
Unicode 1.0 Name Graphic for Negative Acknowledge
Block Control Pictures
General Category Other Symbol
Canonical Combining Class Not Reordered
Bidirectional Class Other Neutral

Encodings

HTML Decimal Encoding ␕
HTML Hex Encoding ␕
UTF-8 Encoding 0xE2 0x90 0x95
UTF-16 Encoding 0x2415
UTF-32 Encoding 0x00002415
C/C++/Java Escape \u2415

Unicode Properties

NFC Quick Check Yes
NFD Quick Check Yes
NFKC Quick Check Yes
NFKD Quick Check Yes
Numeric Type None
Numeric Value NaN
Line Break Alphabetic
Script Common
Script Extensions Common
Indic Syllabic Category Other
Pattern Syntax Yes
Vertical Orientation Upright
Grapheme Base Yes
Grapheme Cluster Break Other
Word Break Other
Sentence Break Other