U+001A "SUB" SUBSTITUTE Unicode Character

U+001A "SUB" SUBSTITUTE is a control character originally defined in the ASCII standard, intended to signal that a specific piece of data should be replaced or ignored, often used in communications and file transfer protocols to mark an erroneous or invalid character. In modern computing, it is most famously associated with its use in the CP/M and early MS-DOS operating systems, where it served as the end-of-file (EOF) marker, causing text editors and command-line tools to stop reading a file upon encountering it. Despite its historical importance, the SUB character is rarely used directly in contemporary text processing, as its role as a file terminator has largely been replaced by more explicit file system metadata.

General Properties

Code Point	U+001A
Version Added	1.1
Unicode 1.0 Name	Substitute
Block	Basic Latin
General Category	Control
Canonical Combining Class	Not Reordered
Bidirectional Class	Boundary Neutral
Alias	SUB (abbreviation) SUBSTITUTE (control)

Encodings

HTML Decimal Encoding	
HTML Hex Encoding	
UTF-8 Encoding	0x1A
UTF-16 Encoding	0x001A
UTF-32 Encoding	0x0000001A
C/C++/Java Escape	\u001a

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