 The purpose of the layout was to place the most frequently used characters, as they were used in Portuguese, in the center of the layout.It was common that the "0" numeral was omitted (in favour of using the uppercase "O" letter), and there were also some typewriters without the "1" numeral (with the lowercase "L" being used to achieve it).Also absent were symbols such as the exclamation mark (achieved by typing an apostrophe and overwriting it with a period using the backspace key), the asterisk (achieved in a similar way, with lowercase "X" and the plus or minus sign — for eight- or six-pointed asterisks, respectively), the number sign (which was achieved by some through intricate methods involving partial depressions of the backspace key to overwrite the equals sign with two slashes), and the inequality sign (typing an equals sign and overwriting it with one slash).