The zero-width space (rendered: ; HTML entity: or ), abbreviated ZWSP, is a non-printing character used in computerized typesetting to indicate where the word boundaries are, without actually displaying a visible space in the rendered text.
This enables text-processing systems for scripts that do not use explicit spacing to recognize where word boundaries are for the purpose of handling line breaks appropriately.
The zero-width space marks a potential line break without hyphenation.
[2] ICANN rules prohibit domain names from containing non-displayed characters, including the zero-width space, and most browsers prohibit their use within domain names because they can be used to create a homograph attack, where a malicious URL is visually indistinguishable from a legitimate one.
Additionally, the character entities , , , and all also refer to the zero-width space, contrary to what their names suggest.