The symbol hash, or pound sign. The symbol has historically been used for a wide range of purposes including the designation of an ordinal number and as a ligatured abbreviation for pounds avoirdupois – having been derived from the now-rare .is known variously in English-speaking regions as the number sign,
|In Unicode||U+0023 # NUMBER SIGN (#)|
|Different from||U+266F ♯ MUSIC SHARP SIGN|
U+2317 ⌗ VIEWDATA SQUARE
U+22D5 ⋕ EQUAL AND PARALLEL TO
|See also||U+00A3 £ POUND SIGN|
U+2116 № NUMERO SIGN
Since 2007, widespread usage of the symbol to introduce metadata tags on social media platforms has led to such tags being known as "hashtags", and from that, the symbol itself is sometimes called a hashtag.
The symbol is distinguished from similar symbols by its combination of level horizontal strokes and right-tilting vertical strokes.