> ## 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.

# Additional fields

> Enable additional invoice fields such as Due Date, Line items extraction, GL Coding, and Taxes in the Document Definition Features dialog box.

You can manage additional fields in the **Document Definition Properties** dialog box.

## Open the additional fields settings

<Steps>
  <Step title="Open the Document Definition properties">
    From the main menu of the Document Definition editor, select **Document Definition → Document Definition Properties...**.
  </Step>

  <Step title="Open the Document Definition settings">
    In the dialog box that opens, click the **Document Definition Settings** tab.
  </Step>

  <Step title="Edit the additional fields and features">
    Click the **Edit...** button in the **Additional Fields and Features** group.
  </Step>
</Steps>

The **Document Definition Features** dialog box opens, offering additional invoice processing options. Each option may involve one or more invoice fields and their associated rules.

## Available additional fields

The **Document Definition Features** dialog box lists the following additional fields:

* Due Date
* Delivery Date
* Purchaser Name
* [Purchase order matching](/flexi-capture/invoice-reader/ir-po-matching)
* Line items extraction (your [license](/flexi-capture/license-manager/license-param) must allow capturing data from this additional field)
* GL Coding
* Prefer variant ID as main identifier in training batch (when the vendor depends on the business unit)
* Taxes
* Additional taxes (available if the **Taxes** option is selected)

Each option in the dialog box is supplied with a description that lists the fields from which to capture data.

## Enable an additional field

To enable an option, select the check box next to its name.

To enable the **Purchase order matching** option, you additionally need to connect to a database storing your purchase orders. For more information, see [Purchase order matching](/flexi-capture/invoice-reader/ir-po-matching).

The names of the fields linked to disabled options are shown in gray. In the data form displayed in the Document Definition editor, these fields are also shown in gray, and they are not displayed during verification in the document editor. When you open the properties of a gray field, the message "Field is disabled by its feature" is displayed.

Rules linked to disabled options are also disabled in the list of rules of the Document Definition.

Once you enable an option, its linked fields and rules are enabled.