Six-Per-Em Space

The Six-Per-Em Space at U+2006 is an invisible spacing character in Unicode’s General Punctuation block. Its width is traditionally one sixth of an em, so it represents a narrow fixed space rather than a word-separating blank typed from the keyboard. Its practical use is mostly in professional typography, page layout, and imported publishing text where fine horizontal spacing matters. Designers may use it between tightly related items that need a small visual gap, such as around initials, in compact tables, or in carefully spaced numeric and unit text, although many workflows now prefer layout controls or ordinary thin spaces instead. Because it is whitespace but not a normal space, it can create surprises in search, line breaking, text comparison, and data cleaning. A string that looks like two words separated by an ordinary blank may contain this character instead, so it is most often encountered when copying from PDFs, typesetting systems, or richly formatted documents.