Zero-width non-joiner

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ISO keyboard symbol for ZWNJ

The zero-width non-joiner (ZWNJ) is a non-printing character used in the computerization of writing systems that make use of ligatures. When placed between two characters that would otherwise be connected into a ligature, a ZWNJ causes them to be printed in their final and initial forms, respectively. This is also an effect of a space character, but a ZWNJ is used when it is desirable to keep the words closer together.

The ZWNJ is encoded in Unicode as U+200C zero width non-joiner (HTML: ‌ ‌).

Use of the ZWNJ and US for correct typography[edit]

In certain languages, the ZWNJ is necessary to unambiguously specify the correct typographic form of a character sequence.

The ASCII control code Unit Separator was formerly used for this.[dubious ]

Correct (with ZWNJ) Incorrect Meaning
Display Picture Code Display Picture Code
می‌خواهم Correct display of Persian with ZWNJ.svg می‌خواهم

(rendered from right to left):
می‌خواهم
میخواهم Incorrect display of Persian without ZWNJ.svg میخواهم Persian 'I want to'
עֲו‌ֹנֹת Correct Hebrew Vav with Holam haser with ZWNJ.svg עֲו‌ֹנֹת

(rendered from right to left):
עֲו‌נֹת
עֲוֹנֹת Incorrect Hebrew Vav with Holam male without ZWNJ.svg עֲוֹנֹת Old Hebrew 'transgressions'
Auf‌lage Correct display of German with ZWNJ.svg Auf‌lage Auflage Incorrect display of German without ZWNJ.svg Auflage German 'edition' (compound of "auf"+"Lage")
Brotzeit Correct display of Fraktur with ZWNJ.svg Brot‌zeit Incorrect display of Fraktur without ZWNJ.svg Brotzeit German (regional) '(kind of) snack'
(compound noun "Brot"+"Zeit" = 'bread time'),
shown in Fraktur

In the Biblical Hebrew example, the placement of the holam dot to the left of the letter vavו⟩ is correct. If a dot were placed over the ⟨ו⟩, it would resemble ⟨עוֹנוֹת⟩, "seasons". In Modern Hebrew, there is no reason to use the ḥolam after the vav, and the ligature is not needed, so it is rarely used in Modern Hebrew typesetting.

In German typography, ligatures may not cross the constituent boundaries within compounds. Thus, in the first German example, the prefix Auf- is separated from the rest of the word to prohibit the ligature fl.

Use of the ZWNJ for displaying alternate forms[edit]

In the Indic scripts, insertion of a ZWNJ after a consonant with a halant or before a dependent vowel will prevent the characters from being joined properly. For example,

In Devanagari, the characters क् and typically combine to form क्ष, but when a ZWNJ is inserted between them, क्‌ष (code: क्‌ष) is seen instead.

In Kannada, the characters ನ್ and ನ combine to from ನ್ನ, but when a ZWNJ is inserted between them, ನ್‌ನ would be seen. This style is typically used to write non-Kannada words in Kannada script. Ex: Facebook is written as ಫೇಸ್‌ಬುಕ್, though it can be written as ಫೇಸ್ಬುಕ್.

Symbol[edit]

German T2 keyboard (detail), showing the ZWNJ symbol on the “.” key

The symbol to be used on keyboards which enable the input of the ZWNJ directly is standardized in Amendment 1 (2012) of ISO/IEC 9995-7:2009 "Information technology – Keyboard layouts for text and office systems – Symbols used to represent functions" as symbol number 81, and in IEC 60417 "Graphical Symbols for use on Equipment" as symbol no. IEC 60417-6177-2.

See also[edit]

External links[edit]