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Unsupported titles/Number sign



# (English symbol name number sign or hash or pound sign or octothorpe)

  1. (set theory) The cardinality of a set.
    #{ 5, 3, 7, 11 } = 4
  2. (computing) The hash character.
  3. (Internet) A hashtag, which is a metadata tag for use in microblogging and social network services, used to label and search content.
  4. (Usenet) Used to pad the left side of a quotation from a manual or official source.
  5. (mathematics, computer science) concatenation
  6. (Should we delete(+) this sense?) (Internet) The anchor in a page.
    1. Used in URLs, links to the anchored portion of the page. goes to the "chapter14" anchor in the index.html page.
    2. The ID selector in CSS, which intends to format an element that appears only once in a page.
      div#currentchaptertitle {font-weight: bold}
  7. (syntax) Used to indicate that a sentence is grammatical but semantically strange.
  8. (phonology) Used to indicate a word boundary.
  9. Alternative form of
  10. (chess notation) checkmate
  11. (cartography) Used to denote a village.
  12. (Should we delete(+) this sense?) (programming) The length operator in Lua.


Derived termsEdit

Coordinate termsEdit

  • (to pad a quotation on Usenet): > (for a quotation not necessarily from a manual or official source)

Usage notesEdit


  • (chess): ++



The symbol # derives from the abbreviation lb for Latin libra (pound), via the medieval convention of indicating abbreviations with a bar, .


# (plural # or #s)

  1. (food packaging, US) Pound (unit of weight)
    3# — "three pounds"
  2. (followed by a numeral: used attributively) Number
    #3 — "number three"
  3. (linguistics) denotes a word or morpheme boundary

Related termsEdit


See alsoEdit