in a rectangular "lozenge" is the most commonly used type of OMR form;
* The most familiar form in the United Kingdom is the UK National lottery form.

Lozenge marks represent a later technology that is easier to mark and easier to erase. The large "bubble" marks are legacy technology from very early OMR machines that were so insensitive a large mark was required for reliability. In most Asian countries, a special marker is used to fill in an optical answer sheet.