> 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/simple-mapping-sub-transformation/options-simple-mapping/parameters-tab.md).
# Parameters tab
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 to make all the variables that are available in the parent transformation available in the sub-transformation, even if they are not explicitly specified in the Parameters tab.
When this option is not checked, only those variables/values that are specified are passed down to the sub-transformation.
|
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