The word joiner (WJ) is a Unicode format character which is used to indicate that line breaking should not occur at its position.[1] It does not affect the formation of ligatures or cursive joining and is ignored for the purpose of text segmentation.[1] It is encoded since Unicode version 3.2 (released in 2002) as U+2060 WORD JOINER (⁠).
The word joiner replaces the zero-width no-break space (ZWNBSP, U+FEFF), as a usage of the no-break space of zero width. The ZWNBSP is originally and currently used as the byte order mark (BOM) at the start of a file. However, if encountered elsewhere, it should, according to Unicode, be treated as a word joiner, a no-break space of zero width.
The deliberate use of U+FEFF for this purpose is deprecated as of Unicode 3.2, with the word joiner strongly preferred.[1][2]