A thin space is a blank typographic unit equal to one fifth (sometimes one sixth) of an em wide. It is often used as an unambiguous thousands separator. It is also used to add space to nested quotation marks.
In Unicode, thin space is encoded at U+2009 thin space (HTML:
). Unicode's U+202F narrow no-break space (HTML:
) is a non-breaking space with a width similar to that of the thin space.
In LaTeX, a thin space is written as "
See also 
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