> ## 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.

# Creating a Machine-Readable Form/Form Identifier

> Form identifiers, typically barcodes, let ABBYY FlexiCapture pick the correct Document Definition when several share the same anchor arrangement.

A **form identifier** is an element of a machine-readable form used to select the correct Document Definition if several Document Definitions have the same arrangement of anchors.

We recommend using barcodes as form identifiers.

A barcode is a set of vertical black and white lines of differing widths used to encode information.

<Accordion title="A barcode">
  <img src="https://mintcdn.com/abbyy/39LtOHLEp1q7pm1x/images/flexi-capture/Bar_code.gif?s=747ecb86fc9e868f2ae200fe565dcc0a" alt="" width="244" height="89" data-path="images/flexi-capture/Bar_code.gif" />
</Accordion>

Other elements on the form can also be used as form identifiers.