Every major braille-producing count

Every major braille-producing country has standards for the size and spacing of braille embossed on paper. In the United States and Canada, the de facto standard is the values put forth in Specification 800, "Braille Books and Pamphlets," from the National Library Service for the Blind and Physically Handicapped of the Library of Congress.
Section 3.2 of Specification 800 (Braille Books and Pamphlets) February 2008 reads as follows: