The No-Break Space at U+00A0 is an invisible spacing character that keeps the words or symbols on either side from being separated at a line break. It belongs to Unicode’s Latin-1 Supplement block and functions as whitespace, but unlike an ordinary space it tells layout software that the adjacent text should stay together. Its most common use is in typography for short phrases and measurements that should not split across lines, such as a number with its unit, a title with a name, or an abbreviation tied to a value. French and other typographic traditions also use it around certain punctuation marks, often in a narrow form when available, to keep punctuation attached to the preceding or following text. It also appears frequently in web pages, word-processed documents, spreadsheets, and copied text from PDFs where alignment or line-wrapping was controlled manually. The main practical gotcha is that it looks like a normal space but is not always treated the same in search, sorting, validation, or command-line input, so a pasted word or number may fail to match until the hidden no-break space is replaced.
In extended ASCII: byte 160 on Windows (Alt+0160)andbyte 255 in DOS (Alt+255)