> For the complete documentation index, see [llms.txt](https://docs.pentaho.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.pentaho.com/pdia-data-integration/10.2-data-integration/pdi-transformation-steps-reference-overview/regex-evaluation/options-regex-evaluation/settings-tab.md).

# Settings tab

![Settings tab in Regex evaluation](/files/NP1ZwECZpCKOqNhYM01b)

The **Settings** tab contains the following options:

| Option                               | Description                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
| ------------------------------------ | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Field to evaluate**                | Specify the name of the field from the incoming PDI stream to be matched against the regular expression.                                                                                                                                                                                                                                                                                                                                                                                                                      |
| **Result field name**                | Specify the name of the output field. This field is added to the outgoing PDI stream and has a value of `Y` to indicate the value of the input field matched the regular expression or `N` to indicate it did not match.                                                                                                                                                                                                                                                                                                      |
| **Create fields for capture groups** | Select to create new fields based on capture groups, in the regular expression. When this option is selected, substrings in the captured groups are extracted and stored in new output fields, that you specify in the **Capture Group Fields** table. Each capture group must have a field defined in the **Capture Group Fields** table. The order of the fields in the table must be the same as the order of the capturing groups in the regular expression. You can change the data type using the columns in the table. |
| **Replace previous fields**          | Select to replace fields from the incoming PDI stream with fields created for the capture group field names, if the fields have the same name. If this option is clear, new fields are added to the outgoing PDI stream for each capturing group field. This option is available when you select the **Create fields for capture groups** option.                                                                                                                                                                             |
| **Regular expression**               | Specify your regular expression. Click **Test regEx** to open the Regular expression evaluation window.                                                                                                                                                                                                                                                                                                                                                                                                                       |
| **Use variable substitution**        | Select to expand variable references to their values before evaluating the regular expression pattern.                                                                                                                                                                                                                                                                                                                                                                                                                        |


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