U+000F "SI" LOCKING-SHIFT ZERO Unicode Character

U+000F "SI" LOCKING-SHIFT ZERO is a control character originally defined in the ISO/IEC 646 standard and later incorporated into Unicode as part of the C0 control code set. It is used in telecommunication and text processing to shift the interpretation of subsequent characters into an alternate, often secondary, character set, with "SI" standing for "Shift In." Unlike shift characters that toggle back and forth temporarily, this is a locking shift, meaning that the shift remains in effect until explicitly reversed by a corresponding "SO" LOCKING-SHIFT ONE character. In modern systems, its use is largely historical, replaced by more sophisticated encoding schemes such as UTF-8, and it is typically invisible in rendered text, serving only as a formatting directive for legacy terminal or printer protocols.

General Properties

Code Point	U+000F
Version Added	1.1
Unicode 1.0 Name	Shift In
Block	Basic Latin
General Category	Control
Canonical Combining Class	Not Reordered
Bidirectional Class	Boundary Neutral
Alias	LOCKING-SHIFT ZERO (control) SHIFT IN (control) SI (abbreviation)

Encodings

HTML Decimal Encoding	
HTML Hex Encoding	
UTF-8 Encoding	0x0F
UTF-16 Encoding	0x000F
UTF-32 Encoding	0x0000000F
C/C++/Java Escape	\u000f

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	Combining Mark
Script	Common
Script Extensions	Common
Indic Syllabic Category	Other
Vertical Orientation	Rotated
Grapheme Cluster Break	Control
Word Break	Other
Sentence Break	Other