Anchor requirements

• Use standard anchors on machine-readable forms: black squares, corners, or crosses. The recommended number of anchors is five: four in the corners of the form (they form a rectangle if imaginary lines are drawn between each pair) and one on a side of that imaginary rectangle.
• If standard anchors cannot be used, use one of the following combinations of elements as anchors:
  • At least two vertical line separators and two horizontal line separators
  • At least four text elements and one form identifier element
  • Another combination of elements
• The distance between the edge of an anchor and the nearest form element should not be less than 3 mm.
• The distance between an anchor and the edge of the page should not be less than 8 mm.
• Print anchors in a dark color (black is recommended) so that they do not disappear during scanning.

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Requirements for black squares

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Requirements for crosses and corners

• The imaginary square drawn around an anchor of this type must be between 4x4 and 8x8 mm. The recommended size is 5x5 mm.
• Anchors of one type must be the same size within one form.
• All sides of an anchor must be of equal length.
• The line thickness for anchors on the same form must be the same, within the range 0.3 to 1 mm. The recommended thickness is 0.5 mm.

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Requirements for text used as anchors

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Requirements for line separators used as anchors

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Requirements for barcodes used as anchors

• The barcode width (the distance between the leftmost and rightmost bars) should not be less than 47-50 mm.
• The barcode height should not be less than 12-15 mm (digits not included).
• The barcode orientation (direction of the bars) should match the page orientation. Scan the pages in the direction of the bars.
• The EAN 13 barcode format is recommended.
• The minimum recommended distance between a barcode and any other form element is 10 mm.