---
source: https://carbone.io/documentation/design/overview/in-template-options.html
title: "In-template options"
description: "Set render options directly inside a template with {o.…} tags"
generated_at: "2026-07-07"
---

# In-template options

Set render options directly inside a template with {o.…} tags

## Overview

Template options let you set certain render options **from inside the template itself**, instead of (or in addition to) passing them in [every API call](/documentation/developer/http-api/generate-reports.md#generate-a-report-request-body). They are written as a special tag:

```text
{o.optionName=value}
```

Place the tag anywhere in the template. It is processed during rendering and **removed from the final document**. This is convenient when an option is specific to a template, so you do not have to remember to send it on every render request.

> ℹ️ **Note:** The syntax always requires a value: `{o.key=value}`. Boolean options take `true` or `false`. A template option **takes precedence** over the same option set in the API render call.

## Available options

| Option | Example | Description |
| --- | --- | --- |
| `converter` | `{o.converter=L}` | Force the conversion engine: `L` = LibreOffice, `O` = OnlyOffice, `C` = Chromium. Only `L`, `O` and `C` are accepted. See [converters](/documentation/developer/http-api/generate-reports.md#converters). |
| `lang` | `{o.lang=fr}` | Set the locale language used by Carbone (lower-cased automatically). See [translations & i18n](/documentation/design/advanced-features/translations-i18n.md). |
| `timezone` | `{o.timezone=Europe/Paris}` | Set the timezone used to format dates. See [timezones](/documentation/developer/http-api/generate-reports.md#multi-timezone). |
| `hardRefresh` | `{o.hardRefresh=true}` | Force LibreOffice to render and refresh the whole document at the end of the process, for example to recompute fields, spreadsheet formulas, or a table of contents. |
| `exportFormattedValuesAsText` | `{o.exportFormattedValuesAsText=true}` | In XLSX output, export formatted values (produced by `formatN`) as text instead of a native spreadsheet number format. See [number formatters](/documentation/design/formatters/number.md). |
| `styleSource` | `{o.styleSource=templateId}` | Apply the style of another DOCX or ODT template. Mainly used to style Markdown templates, see [Markdown templates](/documentation/design/template-formats/markdown.md#style). |
| `useHighPrecisionArithmetic` | `{o.useHighPrecisionArithmetic=true}` | Use high-precision arithmetic for computations in the template. |
| `preReleaseFeatureIn` | `{o.preReleaseFeatureIn=5004002}` | Enable a pre-release feature for a specific Carbone version (used to opt into a fix or feature before it becomes the default). |

## Example

A Word template that should always be rendered with the OnlyOffice converter, in French, and hard-refreshed so its table of contents is rebuilt:

```text
{o.converter=O}
{o.lang=fr}
{o.hardRefresh=true}
```

## Related topics

- [Version lifecycle](/documentation/design/overview/version-lifecycle.md)
- [Template feature](/documentation/design/overview/template-feature.md)
- [Philosophy](/documentation/design/overview/philosophy.md)
- [Getting started](/documentation/design/overview/getting-started.md)
- [Fonts support](/documentation/design/overview/font-support.md)
- [Design best practices](/documentation/design/overview/design-best-practices.md)