> ## Documentation Index
> Fetch the complete documentation index at: https://docs.abbyy.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Checkmark field requirements

> Checkmark field requirements specify recommended sizes from 3.5x3.5 mm to 5x5 mm and a 0.4 mm border line width on machine-readable forms.

1. The recommended [field sizes](/flexi-capture/mrf-requirements/ap-mrf-checkmark-field) are 3.5x3.5 mm, 4x4 mm, 4.5x4.5 mm, or 5x5 mm (if circular checkmark fields are used, they must fit into squares of recommended sizes).
2. The recommended line width for checkmark field borders is 0.4 mm (irrespective of the size of the field).