In written English, the symbol "K" is often used informally to indicate a multiple of thousand in many contexts. For example, one may talk of a "40K salary" (), or call the Year 2000 problem the "Y2K problem". In these cases, an uppercase K is often used with an implied unit (although it could then be confused with the symbol for the kelvin temperature unit if the context is unclear). This informal postfix is read or spoken as "thousand" or "grand", or just "k".