> 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/pba-report-designer/function-reference/common-functions.md).

# Common functions

The **Common** category contains functions that handle page numbering, and a generic OpenFormula feature that you can use to create your own custom function.

| Function Name        | Purpose                                                                                                                                                                                                                                                                                                      |
| -------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| **Open Formula**     | Enables you to create your own custom OpenFormula function using the built-in Formula Editor. This function will run according to its placement in the report. If you need a custom function to run before all other report actions, use the **Open Formula** function in the **Advanced** category instead. |
| **Page**             | Counts the number of pages rendered thus far in a report.                                                                                                                                                                                                                                                    |
| **Total Page Count** | Lists the total number of pages in the rendered report.                                                                                                                                                                                                                                                      |
| **Page of Pages**    | Prints the current page number in comparison to the total number of pages in the rendered report.                                                                                                                                                                                                            |


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