U+2416 "␖" Symbol for Synchronous Idle Unicode Character

U+2416 "␖" Symbol for Synchronous Idle is a graphical control character used to represent the Synchronous Idle (SYN) control code in data transmission protocols. Originating from older telecommunication standards like ASCII, this symbol denotes a signal sent to maintain synchronization between two devices during synchronous communication without transmitting any actual data. It appears as a small, stylized graphic typically resembling the letters "SYN" within a rounded rectangle or box, allowing it to be visually distinguished in plain text or technical documentation. While rarely used in modern user interfaces, it remains important for legacy data analysis, debugging communication protocols, or representing control characters in Unicode-aware systems.

General Properties

Code Point	U+2416
Version Added	1.1
Name	Symbol for Synchronous Idle
Unicode 1.0 Name	Graphic for Synchronous Idle
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 0x96
UTF-16 Encoding	0x2416
UTF-32 Encoding	0x00002416
C/C++/Java Escape	\u2416

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