<character> "#", ASCII character 35. Common names: number sign; pound; pound sign; hash; sharp; crunch; hex; INTERCAL: mesh. Rare: grid; crosshatch; octothorpe; flash; ITU-T: square, pig-pen; tictactoe; scratchmark; thud; thump; splat. The pronunciation of "#" as "pound" is common in the US but a bad idea; Commonwealth Hackish has its own, rather more apposite use of "pound sign" (confusingly, on British keyboards the pound graphic happens to replace "#"; thus Britishers sometimes call "#" on a US-ASCII keyboard "pound", compounding the American error). The US usage derives from an old-fashioned commercial practice of using a "#" suffix to tag pound weights on bills of lading. The character is usually pronounced "hash" outside the US. The name "octothorpe" was made up by a Bell Labs supervisor, Don Macpherson. {Octothorpe story (http://sigtel.com/tel_tech_octothorpe.html)}. (2003-07-05)

hash coding

<character> hash.