# Parameters tab

![Mapping Parameters Tab](/files/iLhw3YS8WiNnSXGeYXrR)

You can use the following fields in the **Parameters** tab to define or pass Kettle variables down to the mapping sub-transformation.

| Option                                                   | Description                                                                                                                                                                                        |
| -------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Variable Name**                                        | Add a string you want to assign as a variable.                                                                                                                                                     |
| **String Value (can include variable expressions)**      | Add the value you want to assign to this variable name. It is possible to include variable expressions in the string values for the variable names.                                                |
| **Inherit all variables from the parent transformation** | Select this option to make all variables that are available in the parent transformation available in the sub-transformation, even if they are not explicitly specified in the **Parameters** tab. |

\*\*Note:\*\* When this option is not checked, only those variables/values that are specified are passed down to the sub-transformation.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.pentaho.com/pdia-data-integration/10.2-data-integration/pdi-transformation-steps-reference-overview/mapping/options-mapping-step/parameters-tab.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.