Page "ASCII" Paragraph 14

Many of the non-alphanumeric characters were positioned to correspond to their shifted position on typewriters.

Thus #, $ and % were placed to correspond to 3, 4, and 5 in the adjacent column.

The parentheses could not correspond to 9 and 0, however, because the place corresponding to 0 was taken by the space character.

Since many European typewriters placed the parentheses with 8 and 9, those corresponding positions were chosen for the parentheses.

The @ symbol was not used in continental Europe and the committee expected it would be replaced by an accented À in the French variation, so the @ was placed in position 40 < sub > hex </ sub > next to the letter A.