Sentence Break

Unicode Version 18.0

Sentence Break is a text segmentation rule that determines where sentences start and end in a string of text, based on punctuation, spacing, and certain character classes like uppercase letters, numbers, or emoji. It operates by assigning each character a specific Break value, such as ATerm, Lower, Upper, or Sep, and then applying algorithmic rules to these values to avoid false breaks after abbreviations like “Mr.” or initials, while still splitting after terminal punctuation like periods, question marks, or exclamation points followed by appropriate whitespace. This enables software to correctly iterate through sentences for tasks like line wrapping, text selection, or natural language processing, ensuring that complex typographic conventions across languages, including those without spaces, are handled consistently.

ATerm
Abbr
AT
Count
4

ATerm is a Sentence Break value marking a period that ends a sentence only when followed by certain conditions, like a space and uppercase letter.

Close
Abbr
CL
Count
197

Close is a sentence break value for punctuation that typically pairs with an opening mark, like a closing bracket or quote.

CR
Abbr
CR
Count
1

CR is a Sentence Break value that marks a carriage return, forcing a sentence boundary immediately after it.

Extend
Abbr
EX
Count
2680

Extend is a Sentence Break value that marks characters which continue a sentence without starting a new one, such as combining marks.

Format
Abbr
FO
Count
60

Format is used for characters that control formatting, like zero-width joiners, which are ignored when determining sentence boundaries.

LF
Abbr
LF
Count
1

LF is a control character that forces a hard line break, terminating a sentence without requiring a following space.

Lower
Abbr
LO
Count
2693

Lower is a sentence break value indicating a lowercase letter that typically begins a new sentence, preventing breaks before it.

Numeric
Abbr
NU
Count
785

Numeric is absent for all Sentence Break values, as they are categorical labels like ATerm, Upper, and Sep, not numeric indicators.

OLetter
Abbr
LE
Count
154159

OLetter is a sentence break class indicating characters that form words, including letters and digits, used to define sentence boundaries for text segmentation.

Other
Abbr
XX
Count
147528

Other is the default Sentence Break value for characters that don’t fit any specific rule, like symbols, punctuation, and unassigned code points.

SContinue
Abbr
SC
Count
31

SContinue is a Sentence Break value indicating that a character continues a sentence without starting a new one, like commas or quotation marks.

Sep
Abbr
SE
Count
3

Sep is the Sentence Break value assigned to characters that act as separators, like line or paragraph terminators, to mark sentence boundaries.

Sp
Abbr
SP
Count
20

Sp is a numeric value indicating the likelihood that a sentence ends after a given character, based on statistical analysis.

STerm
Abbr
ST
Count
168

STerm is a binary value marking characters that can end a sentence, aiding in text segmentation for line breaks and processing.

Upper
Abbr
UP
Count
2011

Upper is a reserved sentence break value used for uppercase letters, indicating they start a new sentence when no explicit boundary exists.