Paper size impossible to encounter ISO standard papers in day-to-day uses, with "Carta" (Letter), "Oficio" (Government-Legal) and "Doble carta" (Ledger/Tabloid) being nearly universal. In Canada, US paper sizes are a de facto standard. The government, however, also uses ISO paper sizes. There is an additional paper size, , to which the name "Government-Letter" was given by the IEEE Printer Working Group (PWG). It was prescribed by Herbert Hoover when he was Secretary of Commerce to be used for US government forms, apparently to enable discounts from the purchase of paper for schools, but more likely due to the standard use of trimming
Seventh Letter year later. Of all the letters attributed to Plato, the "Seventh Letter" is widely considered the only one that might be authentic. R. Ledger defends its authenticity on the basis of computer analysis. Anthony Kenny is likewise inclined to accept it as genuine. The main objections to its authenticity involve its statement that there are forms or ideas of artificial things, whereas Aristotle attributes to Plato the idea that there are forms or ideas only of natural things, as well as the fact that the letter's purported historical setting seems unlikely: the letter implies that Dion's followers wrote to Plato