What is a zero width space used for?
The zero-width space (), abbreviated ZWSP, is a non-printing character used in computerized typesetting to indicate word boundaries to text-processing systems in scripts that do not use explicit spacing, or after characters (such as the slash) that are not followed by a visible space but after which there may ...
How to do zero width space?
The zero width space is Unicode character U+200B. (HTML ​). It's remarkably hard to type. On Windows you can type Alt-8203.